for what you want to do, the 88 CRX HF would be the best since it is the lightest - visually, it is hard to tell the differences between 88 and 91, which are relatively minor - finding one with a Y8 in it probably isn't going to help you much since most people when swapping the Y8 into the 88-91 CRX run the engine as OBD1 rather than OBD2 - you could also run the Y5 as OBD1 with OBD1 ECU - most people with Y8 use the EX P28 ECU which may run too rich for the Y5 (maybe not) - i don't know what other ECU you could use for OBD1, maybe the ECU from VX which is also VTEC, but it would probably not be too good with the Y5 - if you want to run it OBD2, just get a stock 88 HF, get a OBD0 to OBD2 conversion harness from Rywire and drop the Y5 in (you would need to make some minor changes) and put on a good exhaust system (HF exhaust is tiny) - unless you are looking strictly for fuel mileage, you would probably want to also get rid of the HF transmission (very long gears) and get a DX or Si transmission