so one 5770 wasn't enough?
Don't worry about the build - since you've aimed for an Asus board, you'll be pleased with the great manual. An excellent step-by-step guide!
And of course you have us!
And forget the silly ground strap... just touch the case, use common sense and don't touch connectors or components.
The 955 and 965 are the same CPU. AMD overclocked the 955 for you for the extra $20 and named it 965... your choice.
If choosing 955, make sure it's a rev. c3
but I would probably go for 965 too.
750W PSU is way -
way! - more than adequate! What do you have now? If more than 450W, I would keep that for a while...
Don't know if you've already settled for one, but I can highly recommend Fractal Design. Cheap and very, very good.
But how
did the 5770 perform for you?
/edit: btw. your board will need both power connectors to be connected. 4-pin ATX
and 24-pin ATX.