use a p13 (prelude) ecu or a P72 (gsr) ecu. But from everyone says p13 is the way to go. and yes your wiring harness needs to be changed. You want to use your civic wiring harness on your prelude motor connecting to your prelude ecu. Did that make sense??
a h22 into a 94 civic is not just changing the wires and ecu you will need to buy aftermarket mounts and modify your frame a little ...the mounts arent cheap so you better have about 600 bucks before you start your swap..