I know you guys will probably say try it yourself
Well good thing thats out of the way, you know us too well.
No reason why you cant build your own, its all rather simple to do. Its largely just matter of plugging everything into the right places and turning a screwdriver. I should know because I just today disassembled my machine, cleaned it, emptied my water loop, filled it back up , put it all back together and am using it now. You will want to dedicate a day to do it, as it can take a while. Here are some good build guides.
NCIX How to build a gaming PC. Just note that the components used are way overkill for a gaming machine.http://www.youtube.com/watch?v=84NvDMMrCNU
Newegg TV 3-part series, Part 2.http://www.youtube.com/watch?v=d_56kyib-Ls
Part 3 is about installing Windows, drivers and such. Also worth watching.http://www.youtube.com/watch?v=RxaVBsXEiok&feature=relmfu