i have an ep3 snap a picture of the top of the transmission and ill tell you

and congrats on the k. best way to run that motor is get your self kpro. get a good header. skunk 2 stage 2 cams. and upgrade your injectors, throttle body and fuel rail. But don't put a A2 head on it, you would just be wasting your time. and hasport should sell swap mounts for that motor.
To expand on not using the A2 head, simply you will blow your motor up. The A3 motor is an econo motor from the ground up, adding some bolt ons and kpro can help or boost is a very good option as well. but its internals are not designed to rev to 8-9k. They are heavy and not forged, and there is no oil squirters in the block to cool the pistons. So unless you plan on running at the stock A3 red line and adjust the vtec crossover accordingly. That head is a waste of time and money.