To the OP:
As you stated you are pleased with your current motherboard, then I think in your situation you should hold out on upgrading anything (save maybe the SSD) realistically if gaming is your #1 priority on your current system...
Thanks velozzity, yeah max RAM speed of i5s = 1333, so i'd like an i7 so i can get 1600 from it, i had no idea a Sandy could run on my
1156 motherboard so i may look into them now.
Yeah the hyperthreading of the i7s, one of the main reasons for wanting an i7 is that somewhere in the future i can see me having another SLI setup of 2x 580s and i'd need a good CPU to run this so up until now i've been lookin' at the i7 970s.
Anyways great input thanks very much!
*Currently i5 760 OC @4.2

Maybe my first reply was a bit ambiguous but I never stated that Sandy Bridge would work on your mother board which is a socket 1156 board, I was referring to the fact that the only worthwhile upgrade would be moving to a sandy bridge processor and that would require a socket 1155 motherboard. Also no current I7 900 series will work on your board (those are lga 1366 socket), you are limited to a I7 800 series with I believe the I7 880 being the max at the time or you could pick up a I7 875k with unlocked multi for easier overclocking if there are some still floating around out there. I'm not trying to discourage you from moving up to the I7 from the I5, just in real life scenarios you are not going to see any discernible differences between the 2 unless you do alot of encoding/video editing or stuff which benefits greatly from Hyperthreading. Your money is best kept in your pocket or a bank and waiting to skip a generation, or at least till the true successor to I7 900 series and Ivy Bridge are released. Also my upgrade path to my current I7 875k was from a Phenom II 965 at 4.0ghz. My current setup at stock (2.93ghz with 3.6 on 1 core at highest with Turbo enabled) meets or exceeds almost every benchmark I ran while using my AMD system. AMD is good value for the money but in the $200 and above sector they just don't compete really and unless Bulldozer is a miracle cant/wont meet or exceed Intel in the Instructions Per Cycle metric which really gives Intel the lead. The one outlier for this rule is Thuban (6 core AMD based off the Phenom II architechure) which if your main goal is running programs that utilize more than 4 cores does a fine enough job, but until gaming devs get their act together and make more games which scale properly with cores, your best sticking with a good Quad and letting clock speed be king. Also as previously stated the memory speed issue is a non-issue, you will see no appreciable gains in Frames per second unless benchmarking is your priority and not actual gaming.
To anyone else who reads this and says Intel fanboy, all other computers in my household save the one I typed this on are AMD Phenom II based, 1 being a Phenom II 720be tri core and the other being a Phenom II 965.
Also about the ram speed the speeds stated are OFFICIAL suggested Intel specs, not what will really work on your system. Have you tried visiting the memory manufacturers forums to see how you might go about setting up your current memory to work at a faster speed by loosening timings, etc.