id say 8-10 psi would be the max u would want to run w/ stock internals on ur d16 as long as your getting a good tune for it (which if u go to mainstream you will)
Stock internals should be fine for boost as long as you dont get boost happy and up it way too much

vteckidd says hes seen 203 hp out of a non vtec so i dont see the need to put a vtec head on it

And yes, a b16 will be better for the long run, again, it depends how long u think ull stick with this project and how much money you want to spend