Thanks everyone for the very helpful hints.
Franklin--What I consider inefficient: First of all, it's a small case, with one fan(the power supply fan). It has three PCI slots, none of which were utilized when I bought the system. I've added two cards since then(video with HS and wireless nic), which significantly increases the case temp. The computer will just shut down at random times after running for several hours, and will not boot back up for awhile. I open the case and it seems really hot in there, although I don't have a temp guage. After it's cooled for an hour or so, it starts back up, so I'm thinking it has some temp issues maybe? I don't know, I'm just guessing.
Shaner--that Thermaltake Xaser 5000 sounds really cool. Where can I get that? About how much?
Edfair--no riser buscards in this case, but an excellent point to consider.
Madonnac--excellent point about longer cables, thanks.