The wiring on a SOHC VTEC engine would be a pain, simply because they are all ODB-I or II, and a CRX is OBD-0... But its nothing some wiring wont fix... I personally would prefer a ZC, because I dont wanna wire anything up... But I think the better choice, would be a SOHC with VTEC, simply because its a newer engine (less wear and tear), and has plenty of aftermarker support... Compared to the DOHC ZC, which is older, and has little after market support... The SOHC VTEC is also found here (except the B15B, but its virtually the same as the other 2), so getting replacement parts is easy, the ZC is a nightmare... And ofcourse, VTEC is a big plus... A SOHC VTEC engine turboed in a CRX (specially a lighter HF model), would whip some serious ass...