Hiya Bill,
Is this for fun or profit?
If its the latter, I would recommend computer that comes with 24/7 tech support and same/next day service. There's nothing worse than a deadline approaching, and you can't print a file because your computer doesn't work.
It sounds like you're attempting to build a dream machine. So, I would go with dual Xeon Processors and as much ram as you can afford. The 10,000 to 15,000 RPM hard drives would be nice, and having 2 to 3 smaller drives is better than one huge one. Keep one HD for the programs & OS, the 2nd & 3rd could be for scratch disks and the files you're working on.
If you do a search, this has been discussed before.
Checkers