Mobo---either MSI K7N2-Delta2-LSR or EPOX EP-9NDA3+
CPU---AMD athlon 64 3200+ maybe 3400
You've got a socket A board listed with a socket 754 chip. If you want an Athlon 64bit CPU you're going to have to get something like the MSI K8N Neo Platinum:
So make sure you know what kind of board and CPU you're getting because that's a big difference in CPU's and motherboards what you got listed there
But all in all I suggest either you go with MSI or ABit as your motherboard manufacturer no matter if you go AMD64 or just the XP series.
Also I suggest you get the eVGA 6800GT as eVGA puts the same heatsink on all the cards, you'll be able to overclock it to and possibly past 6800Ultra speeds and it'll save you $200.
The ram you have selected is good
And as ak said if you can look into a 10,000 RPM sata drive. Copying files, window loading time, installing files, is all much faster. But if not I suggest you go with Western Digital as the manufacturer, but that's just my personal pref. The best two HD makers I think are Seagate and Western Digital, WD placing #1 in my book