800 on the core is probably too high to start out with. The core is already factory OCed by about 20-25 MHz, and to jump 130 MHz right out of the box might be a bad idea. The core will probably go to 700-750 on stock cooling, but I'm always amazed at people who are disappointed when they can't OC their GPU 100+ MHz. If thats what you want, just be reasonable and buy a faster card.
The memory is rated to run at 1 GHz (2 GHz effective), so you have a "free" overclock there (its set at 972 by default). I think you can set RivaTuner to link your clocks, so your shader will be OCed proportionally with your GPU.