You should just fine with 2 x 6bulb fixtures. When was your last bulb change, or are the fixtures newer?
Montis are definitely the easiest SPS to get your feet wet.... the Forest Fire & German Blue digitatas are among my favorites, and are pretty quick growers once they acclimate. Start them at the bottom of the tank for light acclimation, then slowly move them up to where you want them. If you've never had SPS, they do need fairly strong indirect flow to keep their small polyps clear of debris/detritus..... they get irritated pretty easily if anything is allowed to accumulate on them. They benefit from the occasional gentle turkey baster blowing as well.....