I've seen some other comptuer forums have "Help Me Buy/Build" sections. Is there one here (and I'm blind) or if there isn't, could adding one be considered? I don't know where to put my "$3k Summer Super-computer" comments thread otherwise...
If it's about building your own, I would suggest General Hardware instead of OEM, but yeah...depending on which you're looking to do (build vs buy) I would say that those are the two subforums to use.
If your looking for advice on buying a prebuilt system, put it in the OEM section that the previous poster linked. Otherwise, a self built system would best be commented on in the General Hardware section: http://www.hardforum.com/forumdisplay.php?f=40