Just happen to see this looking for info on this board myself lol. If you have not gotten another GPU go for the ATI 7000 series cheap great performance wise low power consumpition and backwards compatible i got my dad a 6790 at on the same board you have with a phemon II X4 B93 with the new 5001 beta bios 8GB Ram and a 256GB samsung pro 840 ssd along side with his old 5400rpm 1.5 TB and this old hardware is really fast still not as advanced as my FX chips but she can still pack a punch and play all the lastest games on max grpahics do video work nicely but for you if you dont want to break the bank go for a 7770 from XFX if you like nvidia better and want a cheap and decent on there go for the new EVGA 650 i'll post a link for you below if you have the cash tho I would get yourself a 7870 or 7850 from XFX
7770 should be lifetime cheaper then the 2 above and will still pack a punch i'd suggest this with the parts you have if you upgrade go for the ones above otherwise you will see some bottlenecking on the 7870 possible the 7850 and this one below is good the 650
overall for your components i'd suggest the 7770 or any of the nvidias if you upgrade go with the 7800 series ati if you have the cash but i would personnally suggest for your configuration now a 660 with the 2GB of ram or the 650's with 2GB of ram will take away from taxing the system with more video ram but you can definatly update you system to 8GB of ram and with the 5001 bios just about any phemon II series processor none of the FX series but if you don't have the cash for the 7870 or 7850 or the 660 go for the 7770 or the 650 any of the three will be go but aim for more ram and if you have the money ram and interface 192 is going to be overall faster then 128 but 256bit is faster then then 192 but like i said update the processor and ram and bios if you want the 7800 series if your just looking for something over the 8800 get the newer nvidias i listed. I would not give that 8800 away sell it on ebay same with any other parts you sell to upgrade your rig then put it towards your upgrade. The board you have is still a good one and with some upgrades should last you a few more years. Hope this helps you out.