If you haven't bought anything yet, I recomend getting the kit that comes with the MT12 and pipe/header

It will be less money than buying a decent engine/pipe/kit sepeately, and the MT12 is one of the best engines for STs. the Mugen/Novas Rossi pipe is OK,, I run a AE Factory team Pipe. with the Mugen header, it works great.

Any more question, ask away, there aren't too many guys running the MST here on RCU.