You understand wrong

Actually, if your going to boost, the type-r would be WORSE then the LS, just because of the added compression.

If you wanted the best bang for your buck you would get a Type-R head, then add an LS block, which would give a great flowing valvetrain + a good boost block.

And the SiR tranny is geared the shortest, the Type-R tranny is good for its F/D though

On an added note, the Type-R motors take boost GREAT... if you follow up with extensive tuning and don't have the need to run high boost.

The higher compression just gives you a smaller window for screwup in tuning

Doh *edit* Another thing, I think the SiR and the ITR trannys are geared identically, except the ITR tranny has a different final drive and the fact that it is priced way differently If I were you I would just run an SiR.