yeah you can use copper tube to cool the cpu, you can modify a normal cpu cooler i guess, take the heatsink off and put a copper tube onto it.
as about cooling RAM with liquid nitrogen and taking it out, i'm not so sure liquid nitrogen would do the job, it super cools everything and you might have serious issues taking ram out, it might get stuck. so you might have to use some tight rubber, slice it in middle and push it over RAM as collar so that liquid nitrogen won't touch the contacts.
but about custom hardware, YES 100%. think about it, how can you swap RAM without crashing the OS? as soon as you yank the RAM out, your system crashes. same with inserting.
you have to reboot your system and let BIOS detect it, if you do that, your PC will wipe the RAM. you need some forensic hardware that is meant to read RAM as a "usb stick". so you plug it in and it just keeps everything stored without letting it fade and lets you make image of current RAM. i have never seen such hardware tho, but i assume that's what you need, at least that's how i would do it.