I must say, as much I think my current system is hot, your dream system blows my rig right out of the oil well!
Still, I think I'm kinda through paying too much more than $1500-$1750 for a GOOD computer system. I hurt when I bought my first system, a Leading Edge (Daewoo 80286 processor) Model D2 with a monochrome amber monitor and a 30 Mb MFM HD, and Toshiba dot matrix.... and NO 3.5" floppy, all for around $3000 USD! Then years later for about $500 less, color 15" monitor and 40 Mb IDE HD, no printer, a Gateway 80486 (Intel chip). My last system, I paid only about $1000, got a free el cheapo Lexmark inkjet with it, was a HP Intel (Pentium II based) Celeron 466 with a Zip drive (got me hooked!).
But still, I'd back up the guys here who'd recommend the Athlon 64 3000+ chip over the FX-51. It's almost infinitely cheaper (Newegg has it for around $225 USD) and is only marginally less of a performer. But I do believe in maxing out on the video card as far as you can afford it, so as someone said, with the difference in CPU savings, get a top-of-the-line video card, like the Radeon 9800 XT.
Anyhow, anyway you configure it, I wish you the best in obtaining every part of it!