$5K for a C5? Seems really high, like crate motor high. C5 stock is one of the best OEM 4 Cyl motors I've seen, and with no mods will give him a significant jump in power with no special tuning; even the C1 will. Not saying boost isn't a good thing, but a swap can be very effective and totally smog legal too (which can be an important detail here in Ca., dunno about Jersey)

In my R (modded, but all motor), I raced both nitrous and turbo Civics, nitrous Eclipses, and had no problem beating them. JRSC GSR was a little quicker though. Never raced a properly built turbo Civic though