What is the stock psi on the MR and also is there any websites that show how much HP dose every mod gives to the MR?

Stock boost might be the same as the '03 and '04 Evos, since there's only a 5hp difference for the '05s. The earlier Evos were running 19.5psi at peak boost, if I remember right.

As far as gains go, just look for regular Evos. They'll be pretty similar.