ephatch.com
k-series.com

k20a (type r) swaps right in.
don't recall you needing a different wiring harness, just need the motor, ecu & tranny.

k20a2 (type s) motor is the same way.

check ephatch.com all the ep3 questions have been answered on there

do a k20a2 (cheaper and more readily available) and then boost it