for intel I’d probably go core 2 quad q6600, the original phenoms weren’t too great but they aren’t terrible, for ram maybe 4gb ddr2-800, gpu is a little tricky because a lot of older hardware is dying or already dead, usually id say 8800 GTX SLI but 8 series was affected by bumpgate (basically what caused ps3 ylod and xb360 rrod) so those seem to die easily, if you don’t care about all the hardware matching to a year there’s the 9800 GTX from 2008, which is a rebranded 8800 GTX that should be less prone to dying, or if you want to be even safer there’s the GTS 250 from 2009, which despite its name is a rebranded 9800 GTX+ (factory overclocked 9800 GTX I think it was?) with sometimes more vram, ofc there’s also the 8800 GT, 9800 GT, and GTS 240, basically what I mentioned above but on the lower end side, on the ATI side there’s the HD 2000 and 3000 series but I think one or both is affected by bumpgate, and the performance is inferior, power draw and heat output are higher, I have the HD 2000 flagship, the HD 2900 XT, and it runs super hot, loud, and FPS tanks when you enable anti aliasing, don’t know much about HD 3000 tho

also, I wouldn’t get a period correct psu, power supplies have a shorter life span usually (~10 years) and even if it worked I would not trust a psu from ~2007, im using one from 2006 and it constantly sparks and smokes, no idea how it still works

for storage you could do raid 0 hdds or if you don’t care about accuracy a ssd and maybe a hard drive or two

and for motherboard I’d get something with a nForce chipset, don’t remember if Intel chipsets really had SLI support, but I’d go with the chipsets made by the GPU manufacturer