hey guys, i was thinking of getting some extractors and a cat-back system installed on my ST162 Celica ST 1986 model. how much does this cost on average? also, the cat-back system, does that include the muffler because i also wanted to add a sports muffler to get it sounding good and for performance purposes. u guys have been very helpful in the past, thanks for any responses. MIchael 7