Ok I'm new to all this but I need some help. I want to buy a stage 1 stillen supercharger for a 350z, what I wanted to know was if i decided to later on could I convert the stage 1 to and intercooled set up.
Thanks  

I'd just get the stage (< annoying term) 2 supercharger. It comes with a warranty and superchargers have an efficiency handicap so, it would make sense in retrospect to go for the intercooled (still annoying > ) Stage 2 one...  

i'd just get a stage 1 and throw a smaller pulley on it, which will increase the boost to about the same as the stage 2 if sized correctly.  

This is where I'm probably going to sound like an idiot so if anything is wrong, I know....


Well that's true, but then again I think superchargers suffer from windage (or over-spinning) losses specially in a Roots Type superchargers that only work from low to mid RPM's like the one from Stillen. Overboosting it to a degree is acceptable and could put it in the correct efficiency rating, but more boost equals more heat as the air gets compressed more (duh!, I know I know...), so why not just get a one that's intercooled? ECU's use fuel to cool the combustion chamber and stop detonation at times (not to mention the Stillen supercharger comes with its own "7th" injector) so more heat could cause the knock sensor to ruin the fun as more fuel is poured in and ruining the A/F ratio into "save the engine!" mode...

I'm probably overemphasizing thing a bit     and quite possibly got a few thing wrong (if not most...or all; yeah, its all of it....)

I guess it all depends on price and budget and me shuting up

Yeah, I'll shut up... discount what I said.^  

To answer your question OP, yes you should be able to upgrade. My suggestion, as well as a few others, is to just get the "stage 2". You know you're going to get it eventually. You'll be able to run safer, cooler, and make more power. (I think you'll lose a few hp due to the intercooler lowering psi, but that can be easily fixed with a tune.)