coming from someone who has a bugeye with a full sti swap if you are looking at putting in a 6 speed and sti engine make sure you get everything i mean everything. It makes it so much easier and less painfull and the only really way to go bc if you want big power all of your left over wrx parts you dont swap out are going to be the first to fail you. you next question is engine management are you going to rewire your entire car and go drive by wire with your sti set up or stick with your wrx ecu and install a custom cam position sensor and then if you want avcs you need a hydra and a custom set of avcs wires to make them work. i would ask your self if you really want a fast suby or a fast bugeye? buying a sti saves a lot of headaches.