instead of going a wrx swap route, why not consider building another 2.5 from the bottom up? If you get a closed deck you can run mad boost, and then as you build up the block you can put on whatever you want, this is what I think I'm going to do. I've heard that turbo-ing the stock 2.5 block will pose problems with the exhaust port or something crazy like that, either way if you build another engine, then you can rag it out and have a back up....