So it's like this guys...

I just got a 90 GS...its in good shape. I want to know if I should get some bolt ons or (like my friend is telling me to) get a ZEX kit.

If bolt-ons...
which ones? how much money? how much hp? (I want 30 hp for under 600-700 or so bucks)

If nitrous...

(ZEX kit seems to be a good choice since it activates only when turned on and at full throttle (instead of a gay button or what not)

but what shot is safe for a 90 gs with 140 k? what do I need to do to check if it is safe for nitrous? and I can't let my parents know I have it, so is it possible to hide the bottle in the spare tire well and to hide all of the lines incl. in the engine bay?

By the way guys, I'd really appreciate any other ways you have of getting me 30 hp for under 700 or 800 bucks (besides nitrous) because I just dont have the money to turbo or waste on ls/vtec.
Thanks!