I personally don't see a point in multiclassing from Monk to Sacred Fist. Stat-wise, lvl 20 monk vs monk10/10 sacred fist hit's faster, does 1d20 +3 vs 1d12 +1 damage, has spell resistance, dr, and quivering palm, plus cool glowy eyes and (I think) better saves, and it moves faster! rp-wise, there is no reason to become sacred fist, as opposed to just playing a devoted monk.
I agree with IDii, the descriptions and stats and requirements of the Sacred fist all point to a cleric as a base class.