Mad props for not just countering the bad room with pure volume.

These are how i deal with the worst rooms, take what you need, put the rest on a shelf for when a worse room comes.
I do a lot of "Church Rock" stuff in those kind of tough rooms. The number one rule of making things sound good is controling stage volume. The rule of thumb for me is make sure the house is 6 dB louder than the stage whatever the stage is and if possible keep the stage under 95. I know that sounds insane but the best way to kill a mix is to have fight to keep the mains sounding in your face while the reflections off the back wall are makinging everything extremely dull. Generally you will find the low mids to be really sloppy in a church and that will only be made worse with the rear lobe off of wedges. Use ears if its possible, even if the band doesn't like them. This is after all about the audience enjoying the show. They make all the difference in the world. When it comes to amps Bass amps will generally help matters however guitar amps really create problems. Guitar amps on a lower stage or in a single level room will be aimed at the front row and blocked by the bodies in the room further adding to the low mid "Blah" that quickly gets out of control. If its possible put them off stage in a sperate room and pipe them in or use, dare i say it, PODs or the like. The live cymbals will also give you a huge headache, the opposite of conventional wisdom applies in extremely live rooms, go with a live kit and V-cymbal. The kit won't give you many problems but having someone ride on a crash during a bridge or the like will drive you volume level up 3-6 dB without the cymbals being miced and really foul up the overall mix by getting into every mic on the stage. Also, unless you are micing cymbals use ALL dynamic mics as once again you will be fighting cymbals in everything. It doesn't help a lot but it does help a little. Try and keep the nulls of the choir mics pointed at the drums even if that makes the mics point in a strange direction or keep everyone on their own mic.
If you haven't stoped reading by now I'm sure you are thinking that this is the number 1 way to rob all life from the music but I promise you the audience will enjoy this more than not hearing anything more than a mush of blah that is made up of the most wonderful amps and drums possible. You should be able to get a good balanced and full sound at about 100-105 with a setup like this. If you go the traditional route with wedges and amps expect to have to push things to 115 or louder before you begin to approach the same fidelity. Even then, it will still sound more sloppy and you are going to get into major feed back problems. More than anything, don't push any frequency group to hard, do whatever it takes to keep things sounding flat in the room and the vocals audible and intelligible and your audience will walk away without saying its to loud and won't bug you to turn up the vocal. You should probably leave the reverb at home. Go with a short delay instead and let the delay trigger the reverb that is already in the room.
I know much of that sounds crazy but this comes from 10+ years experience dealing with these situations. Just remember 95% of America can't tell a tube amp from a pod or if they can doesn't care next to hearing a well balanced mix and intelligible vocals when it come to a live show.
Golden Rule of Live Sound: Its all about the audience, not the band, music, tone, amp, etc.