Dont bother with the TT swap unless you know what you're getting yourself in for. JDM swaps will not pass emissions in GA (ask me how I know ). It's a dirt cheap motor because the Legacy platform is almost more common than the WRX overseas, it'll be a PITA to tune and find parts for. You can get Ej205 motors out of a WRX for next to nothing or pay more money for a nicer STI 257. You'll need to upgrade the tranny so it might be worth it to buy a wrecked car for the harness, motor, tranny, ecu, etc.

I'm sure Batlground or Topspeed could do the swap for you but it'll cost money. You dont have to swap the entire wiring harness like YungDz said but you will have to do a lot of splicing, especially with a newer drive-by-wire STI motor.