I have an AMD Threadripper 1920X, (not) cooled by an Enermax Liqtech 240 TR4. The build is not even a year old and CPU temps are... bad. The mobo is an ASRock X399 Taichi micro ATX board, and the case is a matching Corsair Carbide Air 540 I believe.
After booting into Windows, I look at temps...
modular means you dont have a stack of cables, you can pull some out of the psu, making more room and less chaos with the cable (see pictures of any psu marked as modular)
i think most reviews dont go under the x1950 series nowdays so i guess you'll have to find one with one card and one with the other which both have a similar card in it (like a x1950 pro)
head to the mobo's site and download a bios update and apply it. if ur lucky it will work(dunno anything about ECS), if not then you'll have to find a P965 board at least
well for an upgrade i'd suggest getting an AM2 board and cpu. reason is its a good idea to have 2 gigs of ram under vista (tho not necessary) and i dont know if you want to spend that ammount of money on ddr1 modules (considering future).
as i recall, the only fuss about hardware change is you...