Here is an idea...why not just ship a RTi here and put what ever engine you want in the car.....There are tons of ways to make this happen....the absolute cheapest way would take time...but you just have to pay the cost of the car....which if you know the right people...probably would be less than 3-4K, here is how I recommend this;
First off, either make a friend or find someone in Japan who is in the military about to move back to the states.....this is for 2 reasons, 1....on base people have to deregister their cars prior to moving and sale them, otherwise the car itself can not be resold once they are gone....so cars on bases usually sale for really cheap...I bought my civic for 150 US dollars, it was a gen 5, and on to reason # 2....the military includes one car in the PCS shipment for free, most "single military" members overseas do not even own a car, so this part of their shipment is usually not used....and the shipping is free....but it will be a hassle for the individual having to deregister the car and prepare it for shipping so make sure to pay him a little something in return...
Just an idea, it worked for me at times.