The SGT i think is the Legacy 4th gen (2003-2008) and the turbo model is called a GT and its single turbo but i dont know if this is what hes talking about.
factory compressed will lower it but handle like poop, lowering springs use a thicker coil so it keeps the ride firm. Do this, dont compress springs. If you want some call me at work.
No one ever starts off as a fan of the v7 shape it does grow on you. And there are elderly people that own later model STI's (waits for me to be hit by lightning or a fist)
14-16K can buy alot of car, For that money you could get a nice v7 sti or even a v8. But for only a my05 wrx it seems a little much but thats just me. Why not look at the GC8 imprezas?