need help picking a new motor

i've agreed to buy my friends 90 legacy 5spd sedan for $500. the only problem is that he threw a rod. i was gona swap the old motor for a new one.

he has a turboed EJ25 (built BEFORE the STI came out state side)under the hood. i was thinking of getting a twin turbo EJ20 or a reg. turbo EJ20(i was gona rebuild the old turbo and slap it on) but i don't know where to get the ECU for the EJ20 motor. then i was thinking of a EJ25 so that i don't have to swap out the ECU and then just take off what i can from the old motor and put it on the new one(such as the HUGE freakin turbo) but then i would have to buy reinforced crank, connectors and pistons to handle the stress.

thanks for the help. i should have the title in hand sometime next month unless something comes up.