Here we go again....Quick replies please, buying tomorrow

As some of you will know, about 6 weeks ago I bought my new system (specs below) and have been very happy with it to date but I have got the "need for more speed" syndrome and would like to ask the opinion of some of you specialists out there.

I am currently running sli and have been very happy with it's performance to date with the exception that the GPU's do not have enough power, I still get some stuttering during gameplay in Farcry and FEAR, obviously Oblivion could do with some more grunt too.

I have committed to AM2, at least until I can find someone that wants to buy what I have and then could possibly look at C2D.

I have found a buyer for my current video cards and also for the cpu so I was looking at the following for replacement options, I can't go much further because of financial constraints, also please note that I am in Australia and the prices over here are very nasty compared to the prices in the US. I have included the links to newegg for the items I am considering for your convenience:

AMD AM2 x2 4200+ 65W
http://www.newegg.com/Product/Product.asp?Item=N82E1681...

2x Gigabyte 7900GS OC incl Zalman Cooler
http://www.newegg.com/Product/Product.asp?Item=N82E1681...

Antec NeoHE 550W PSU
http://www.newegg.com/Product/Product.asp?Item=N82E1681...

Since I have had very good results with sli I have chosen to opt for that again, I have compared 3DMark06 results for sli 7900GS OC systems with 7950GT systems and the sli setup seems to fare much better, as does the dual core cpu.

I have not had much success with trying to OC my current system so I will not be looking for immediate OC results, but when/if I can sell my motherboard I will possibly be looking at the GA-M59SLI-S5 http://www.newegg.com/Product/Product.asp?Item=N82E1681... as a replacement, this board supports much better OC capability from what I have been able to find out.

Any comments would be appreciated and will be taken into account before my buying spree starts. Another thing to consider is that I tend to replace my components fairly regularly so I don't think I will get stuck with these cards once DX10 cards come down in price but I do expect to drop a few dollars in the long run.