I've always liked the saying that a crappy rig in the right location will sound better than a great rig in a crappy location. if you're able to dial in the mix just right, I predict you will have some smokin recordings whether you're using c4's, 390's, or shoepes.
If you're gonna have more than one gig with these guys, I would experiment a little. After trying cards, try some spaced omni's, maybe that will help with having "too much stereo seperation" as Wayne said. there's no phase issues with omni's, but maybe try to get one kinda close to drums and the other kinda close to guitar amp. I'm outta my league here with this, so if someone has better omni suggestions that would work with the strange stage setup please chime in.