What I suggested in another thread for a "fists of lightning" was an increase to crit rate in addition to a trait that restored some TP for every crit. That would give monks a lot more longevity in fights, especially given the bonus in crit rate from internal release. Or even just make the crit->TP restore the effect of the stance. Personally I'd prefer this to a stance converting mp to tp, just because I feel it works better thematically.