The difference between 74 and 77 FPS is unnoticable at all ; ).
On both it will run as smooth, the quad should have better minimum frames.
Regarding higher minimum frame rate, that's baseless assumption. Take Crysis from bit-tech's review for example, the i3 530 and Phenom II X4 965BE at the same clock speed pretty deliver identical frame rate (both minimum and average) with a 5870. However the i3 530's frame rate start to get ahead when overclock to beyond 4.0GHz, when the Phenom II X4 965BE refused to go beyond 3.83GHz stable.
I got nothing against AMD Quad...and I do think they are great for their price. But if I was to use one, I certainly will not use one at
stock speed. While OcUK does do overclocked bundle system for 955BE, it is only moderate overclocked from 3.20GHz to 3.60GHz, and is using a old 760 chipset board. I actually made a post to ask Naithwrath if OcUK would consider doing a higher overclocked 955BE bundle (i.e. 3.80GHz+) on a 8xx chipset board that got USB3.0/SATA 6Gbps port, but I think he missed the post and I never gotten a reply. Sure there's the X6, but besides encoding and other software that use all 6 cores which they are great for, it has been proven again and again that it simply offer no extra performance over the x4 for gaming.
When it comes to raw power, Phenom II X4 ain't exactly in the same league as the i5/i7 (they are more around the same league as the Core2Quad 9550/9650). So I think for mmos and games in general, either get the i3 530 4.40GHz overclocked system on a budget, or a i5/i7 4.0GHz overclocked system/bundle if he has no problem paying the extra.
jnr if you could wait, wait for couple more weeks for the launch of the ATI 6000 series card before ordering a system, and then see how it compare to Nvidia performance/price wise and then decide on which graphic card to get. I think CPU/system wise, a overclocked i5/i7 4.0GHz build is the best bet (since you already stated you won't be overclocking yourself), as mmo is arguably one of the most CPU intensive category of games (with lots and lots of people raiding together)...more so than most FPS games.
One thing to note is the the motherboardboard that OcUK use for the i5 overclocked bundle/builds don't support Crossfire/SLI, so if you want Crossfire/SLI, you would most likely need to go for i7 overclocked bundle/build.