Look the reality of your situation is that you are working with a economy engine with a automatic transmission. Your best bet for a fun amount of power would be to do a 5 speed swap and a GSR, LS, or B16. There are no NA bolt on's for B series or D series that gain any real power when the internals are in stock form. Don't waste your time or money on under-drive pulleys.
After the swap your best bang for buck is boost. All the B series engines are great platforms for low level boost in stock form.
After the swap your best bang for buck is boost. All the B series engines are great platforms for low level boost in stock form.