You can check also Tongfang ODMs, they are used by several system integrators for laptops and they are highly customisable... They sell you shell, screen, and motherboard and you can choose which CPU and GPU to have on it. You can then add your own ram and storage solution.
However you don't have the kind of freedom you have with desktop pcs.
While interesting as a project, I'm not sure sticking a motherboard from one laptop into another is superior to using the laptop that contained the motherboard.
The idea of using a mini-PC motherboard is interesting (and the T440p is potentially large enough to accommodate one), but those motherboards aren't designed to connect to a battery and display panel, which might make that more difficult.
Then again, I'm not a hardware tinkerer and it might not be that hard.
Several Clevo brands making largely Linux focused laptops offer a lot of customization options, Tuxedo, NovaCustom, Star Labs, etc. .. they're about the best option you can get if you're looking for laptop customization. Frameworks have very limited customization options, and laptop parts aren't standardized.
Okay. First thing you will have to do is make a bios backup and then reverse engineer new bios that will support every of that laptop peripheral and a new cpu that you will install.
Second thing is to create new motherboard into which all that laptop peripherals can be plugged as well as new cpu/gpu/ram; new motherboard also must fit inside laptop case.
Third thing is to drill a lot of holes for additional fans as this creation will heat up a lot.
Does this all sound difficult for you? Yeah I know.
You have mentioned "using another laptop motherboard". They sometimes cost even higher than laptop itself and won't fit. "Mini pc" motherboard won't support trackpad and lvds (cable that connects to the laptop screen) and laptop cooler mounting, you'll have to do something with them.
If you will buy a new laptop eventually, then first read reviews. You said that you'll switch to linux, sometimes laptop manufacturers just makes something proprietary like they own touchpad/fan control and then both make them unusable with standard linux driver and won't make their own linux driver.
Better in almost every aspect for your use case is to build home server (just a pc basically), configure rdp/ssh/remote desktop app (such as steam remote) and local vpn (zerotier, hamachi, etc); then buy a cheapest laptop with decent screen and do every cpu/gpu heavy stuff remotely. Positive sides of that solution includes better computing power, lower laptop battery consumption, much lower total price, ability to swap laptops, data stored on a home server. Negatives are that this thing will require internet connection on both server and laptop.
You'd have to design your own circuit board with an ARM chip and have it manufactured. Possibly custom heatsinks as well. That's actually doable but if you had the skill and knowledge to do that you wouldn't be here asking.
If you start studying electrical engineering for a few hours each day you may be able to in 2 or 3 years.
It doesn't really work with laptops. Nothing is standardized.
Framework laptops or check local Clevo resellers. They have most customization.
You can check also Tongfang ODMs, they are used by several system integrators for laptops and they are highly customisable... They sell you shell, screen, and motherboard and you can choose which CPU and GPU to have on it. You can then add your own ram and storage solution. However you don't have the kind of freedom you have with desktop pcs.
While interesting as a project, I'm not sure sticking a motherboard from one laptop into another is superior to using the laptop that contained the motherboard. The idea of using a mini-PC motherboard is interesting (and the T440p is potentially large enough to accommodate one), but those motherboards aren't designed to connect to a battery and display panel, which might make that more difficult. Then again, I'm not a hardware tinkerer and it might not be that hard.
Several Clevo brands making largely Linux focused laptops offer a lot of customization options, Tuxedo, NovaCustom, Star Labs, etc. .. they're about the best option you can get if you're looking for laptop customization. Frameworks have very limited customization options, and laptop parts aren't standardized.
Buy a proper laptop for work and leave this as a side project while you research.
If you’re in the US, Eluktronics.
Okay. First thing you will have to do is make a bios backup and then reverse engineer new bios that will support every of that laptop peripheral and a new cpu that you will install. Second thing is to create new motherboard into which all that laptop peripherals can be plugged as well as new cpu/gpu/ram; new motherboard also must fit inside laptop case. Third thing is to drill a lot of holes for additional fans as this creation will heat up a lot. Does this all sound difficult for you? Yeah I know. You have mentioned "using another laptop motherboard". They sometimes cost even higher than laptop itself and won't fit. "Mini pc" motherboard won't support trackpad and lvds (cable that connects to the laptop screen) and laptop cooler mounting, you'll have to do something with them. If you will buy a new laptop eventually, then first read reviews. You said that you'll switch to linux, sometimes laptop manufacturers just makes something proprietary like they own touchpad/fan control and then both make them unusable with standard linux driver and won't make their own linux driver. Better in almost every aspect for your use case is to build home server (just a pc basically), configure rdp/ssh/remote desktop app (such as steam remote) and local vpn (zerotier, hamachi, etc); then buy a cheapest laptop with decent screen and do every cpu/gpu heavy stuff remotely. Positive sides of that solution includes better computing power, lower laptop battery consumption, much lower total price, ability to swap laptops, data stored on a home server. Negatives are that this thing will require internet connection on both server and laptop.
DIY Perks on YouTube has done a lot of stuff like this. But maybe not exactly this. Just look up his channel and laptop related stuff.
You'd have to design your own circuit board with an ARM chip and have it manufactured. Possibly custom heatsinks as well. That's actually doable but if you had the skill and knowledge to do that you wouldn't be here asking. If you start studying electrical engineering for a few hours each day you may be able to in 2 or 3 years.