going by your SAU details you are 17.
i am no angel on the road, nor am i an old wise man at 21.
But i think a 300rwkw car with a 17 guy at the wheel could be a pretty wild mix, (re: Mines_Datsun)
maybe just get used to the car for a while before you go building a monster motor. I'm not having a go at your driving abilities.. i am mearly thinking about what could/would have happened to me if i had a 300rwkw car when i was 17
ON TOPIC:
8.5 CR is as joel said, a nice compromise and will take a fair bit of boosting.
get a rebuild done with forged pistons and if you can afford it, forged rods. Build it once, build it right. The advantage by doing it now is so you can always boost the crap out of it in the future.
If i went down the path of building a monster motor straight up... i'd be driving it by now, but i spent alot of money of temporary go fast parts that could have been better spent on a new engine build.
*one more thing.. can you type english and not sms style shortcut text ?? please