Manual will handle extractors, exhaust, hi-flow cats, OTR intake and tune (approx 240rwkw) without a problem. It will also handle a cam (approx 290rwkw) if you drive it nice. If you give it a real thrashing, then in time as with any car you will need to change the clutch. My car was just dynoed at 253rwkw, it is manual with stock clutch and goes fine... no problems at all. I would definitely recommend a manual over an auto though... they go a lot better, plus their more fun to drive and will take more power without needing high stall and a rebuild =)
Also, please try to post in the right section of this forum next time