scoobiets

So I have a 2003 Subaru Impreza TS 2.5 Wagon. I also own a 2005 Mazda Rx8. I'm selling my Rx8, and if it sells in the next month I'm going to do a swap on my TS. If it doesn't sell within a month then I may get a greddy turbo kit and the mazda maniac upgrade and throw it on the Rx8. I'm trying to figure out what I should swap into it and whats the best way to do it. I'm thinking a awesome swap would be to take the EJ25 out and put in an EJ20 Turbo with the 6 speed. Possibly the EJ207 since I hear its the best of the bunch. I'm also reading that many people swap in the ej25. Is this the same ej25 that comes in my TS? and if so what do I need to do to it to get it going good? I would maost likely still do a swap for a newer ej25 if I did go that route seeing as mine has 158k miles on it. Who knows how hard this would be, and could give me some advice on getting it done? I know from some research that pretty much every Subaru engine can be swapped with another Subaru engine as long as it's post 1990 via eastcoastswappers, but is there another engine that would give me more bang for my buck? Also, which car would be a bette idea to work on if the Mazda doesn't sell? Would and STI Wagon be faster that a nearly 400 whp Rx8?