From 30' back I would recommend using cards, unless it's a very quiet room. Omnis may be good if you can get close and above the crowd chatter.
Speaking for myself, even if I get a stereo board feed I usually mix it down to mono for a matrix because the house mix will conflict with the stereo image created by the mics. On the other hand, if it's a really nice-sounding stereo board mix (rare in my experience) and a noisy room, you may want to go with mostly soundboard in the mixdown and just leave a little of the mics in for ambience.
I agree that if no one can tell you what kind of mixed out jacks are available on the console then definitely go prepared with RCA plugs, XLR-F connectors AND 1/4" plugs. I've never come across the need for XLR-M myself -- doesn't the signal always travel in the direction of the plugs?
If you're using two different recording devices, be aware they
will be audibly out of synch when you mix them and you will have to correct for this. I use Voxengo's freeware r8brain program to "fractionally resample" the board source in this situation, see this post:
http://taperssection.com/index.php?topic=97244.15Once you've calculated the differential between the clocks on your two recorders, you should be able to use the same resampling rate every time.
If you're not close to the stage you will also have to align the board and mic tracks to compensate for the delay in the sound reaching your mics, which will otherwise cause an unnatural echo effect.
You will love making matrix recordings, have fun!