I thought the same thing for many years, and I made it work for a while.
Eventually you will get tired of swapping engines/headgaskets/etc ad infinitum. What do you plan on doing about the HG problem? I used copper spray sealant on my HG and over torqued them by 10ft lbs, the last 2 builds never blew or leaked. But because I increased the boost, I blew the ring lands off a piston. The heads crack because they dont cool well enough and the water jacket walls are to thin. There are 3 gens of heads, the 3rd being the best, but they will crack if overheated enough. Also the passenger side head gets coolant last and its next to the turbo. Building a EA82T to handle more boost takes $$$, you cant do it on a budget......trust me. Search and read my threads about my RX here and in the Retrofit Forum, you'll see what I've done in the last 5-6yrs.
You will need to swap out the wiring harness for the interior also. The sending units for both cars are different, gas, oil, temp, etc.
You've got a lot of work ahead of you. I might have done it 10yrs ago, but its not worth all the trouble anymore :-\
And this is a warning to GD - If you post in this thread, I'll delete it.
Just forget you ever heard of the EA82T.