As long as you get a cable throttle manifold it won't make a huge difference. I was a dumbass and got a DBW one. However I wanted to keep my separate IACV, so I went with it and modified the manifold (It was an 06 impreza). Earlier 00s are your best bet.
Check on the classifieds on here and other forums. More often than not, things are half the price of even ebay lol.