^^^^ that is actually VERY simple to do, well not simple but very possible. theres a audi Quattro replica in austrailia with a wrx frame/driveline and the inline 5 motor its sweet.
id love an I5 in my car and imo easier than a 2j and able to keep awd. and the aftermarket while little to none, again wouldn't be a huge deal. just a decent amount of custom work.
dream swap, awd 2j in my wrx. 2j rwd in my wrx, h6 turbo in my wrx.