The Church Audio are definitely the way to go. I've got CA-14 omnis that just plain sound good.
As has been mentioned above, you really don't need a preamp for an amplified concert--even your fingerstyle guys are probably going through a PA system. That might be a money saver.
The big choice is cards vs. omnis. If your audiences are quiet, omnis sound more natural, are more forgiving about placement and are richer in the bass. Or with the money you save from skipping the preamp, get both and deploy them depending on the situation.