Hi there,
OK easy question first, will this board take an 8800GS card.... Yes, there shouldn't be a problem with this.
RAM upgrades might be a little harder to sort out. The fastest modules I have found that will work on this board are 1066MHz but this is only from research and not from hands on experience. Although these modules are from Crucial UK they might give you an indication of what to look for:
http://www.crucial.com/uk/store/listparts.aspx?model=GA-M61SME-S2%20(rev.%202.0)&Cat=RAM The modules shown in this list are guaranteed to work on the motherboard and, being totally honest, the difference between 1066 MHz and 1300 Mhz is negligible in real world situations.