Can I just go for any CPU? Like AMD Sempron 145 2.8ghz? YES
How about 4 gigs of corsair ddr3 ram?USUALY LITE COIN IS THE SAME RAM AS VRAM
How big of a harddrive should I get? JUST FOR THE OS
I plan on running 4 cards,YOU WILL THEN NEED A RISER FOR AT LEAST ON OF YOUR CARDS so how do I power all four cards with a power supply? THEY EXIST UP TO 1600W it depends on your cards Do I chain them together somehow?yes but I don't know how, but lok in the search
Also, how do I get a bootable of windows 7 onto a thumb drive. no too big, try A CHEAP HARD DISK