The mainstream supercharger avaiable for 5th gens with the Jackson Racing one. Its upwards of 3,000 dollars but I hear it's pretty sweet.

Aside from oilchanges every 3k, the prelude's maintenence isn't too bad. I don't have specific numbers, but it's a reliable car. Main repairs you'll have to do around this time in the prelude's life are the timing belt and clutch.

Good luck, keep us posted when buying one