$800 Budget Asus Crosshair Build - Please Help Me Finish

Well, I was finally talked out of upgrading my existing AGP platform... I was going to upgrade to the new sapphire 1950x pro agp card, but instead I decided to build a budget crosshair system.

My budget is $800, and here is what I have so far:

Used (but in new condition) mobo/video package: ($480)

-Asus Crosshair Motherboard
-AMD Athlon 64 X2 4200+ Windsor 2.2GHz Socket AM2 -
-XFX PVT73GUGE3 GeForce 7600GT 256MB 128-bit GDDR3 PCI Express x16
-1 Gig (2x512) DDR2 PC2-6400 • 4-4-4-12 • UNBUFFERED • NON-ECC • DDR2-800 • 2.2V • SLI-Ready • 64Meg x 64
-54 MBPS WIRELESS G PCI ADAPTER WG311

Brand New Case Combo from Tiger Direct: ($130)
-Cooler Master Ammo 533
-Ultra X-Connect XVS 600-Watt Power Supply
-Lite-on SHM-160P6S 16X DVD Burner

-Seagate 320GB SATA-II $80

-2nd case fan (Ultra 120mm Ball Bearing Fan Blk/Titanium ) $5

So far, this has totalled almost $700, leaving me $100 to play with or save for a better upgrade a little later.

My first question: will this system be faster than the x1950 pro agp upgrade solution? My AGP system is an athlon xp 3200 with 1 gig RAM.

2nd question - what's my best upgrade path over the next couple months? Obviously I should upgrade the video card, RAM, and CPU, but what's the most cost effective method? Should I ditch the vid card and get an x1950 pro, or should I get another identical GeForce 7600GT and run in SLI?

If that's the case, should I use my left over $100 to hunt for a used GeForce 7600GT on ebay and upgrade my video right away? (but I guess that would likely mean upgrading my powersupply too wouldn't it?)

Any help greatly appreciated!!