I got my H22A1 from a local friend who totaled out his Lude (massive rear damage, wasn't his fault, he was able to buy the car back for cheap).

My friend with the 99EX B18C3 (JDM SiR-G) powered got his from ardperformance.com, and another friend with a 93 Si Hatch got his B18C5 from inlinefour.com