If you're not overclocking, there is no difference between the B3 revision "SL9UM" and the G0 revision "SLACR" for a gamer.
Even if you wanted to overclock, both can get to 3.0 GHz.
My B3 revision gets to 3.3 on intel heatsink, prime stable, and booted into windows at 3.7.
I would recommend, that if you're not going to overclock, then you try and buy something with a higher clock speed, such as the E6850 at 3.0 stock.
Games do not take much advantage of the 4 cores yet, and so, the dual core E6850 at 3.0 stock would be a better option.