If you have a DX, you could do a mini-me swap (just swapping out the head for a d16z6 vtec head) which would gain you a few horse power.

IMO, you'd be better off swapping to a complete d16z6 motor, transmission and ECU, which would give you the additional few ponies, plus a more useful gear ratio. This also leaves you open to future modifications, which is a good thing, because you'll probably get bored pretty quick