trac3ur4

Hi I have a 99 L series impreza and Im looking into doing a wrx swap. I would do a sti swap but dont know if that would be more of a hassle with the 6 speed tranny. Looking for a decent swap where i can just pull and drop without much modifications. The wrx model would be fine just dont know what one swaps over easiest. If someone could help me out with letting me know whats the easiest engine that has decent power and where i the wiring may not be a huge hassle that would be great. Just need info like will wrx tranny fit right in? Do i need to change cross member? Just wants this to go as smoothly as possible. Any help is greatly appreciated