Its a good motherboard,but 8600(any model) is a weak card for gaming, so definitely consider something better.
Also get 4GB RAM especially if you use a 64bit OS because some games benefit from more than 2GB RAM
Yes the board is good. Though your system is completely not optimized for gaming.
There is NO need to go with an X58 system for gaming with anything less then 2 GTX480s which would run you about $1000 just for the cards.
I'm unsure on your budget but would suggest getting a AMD Athlon II X4 build with 4GB of RAM and a ATI HD 5770. This type of build should run at a similar price to your current one but would performance much much better.
If you want some good build advice go post in the "Systems" section.