Although not in an art gallery, I do similar set-ups like this on a weekly basis. In many cases, and this would definitely be one of them, I use my CA-14 omnis. Depending on how they position their instruments, I would essentially use 1 stand, between 2.5 - 3 feet high, and place it between their monitors, aimed ever so slightly towards the bass an drums. you will pick them up plenty, as they will be loud enough. The added advantage of omnis in this type of situation, is that you want some ambience, but your proximity to the band will overpower most of the audience's chatter and applause. With jazz, in general, you should probably ask the drummer if he'll be using sticks or brushes. A jazz drummer can be very loud if using sticks. If you have access to any of their live performances, give one a listen in advance to get a sense of what is louder than what, and set up accordingly. Keeping a small footprint is easy with this set-up...additionally, if you'd like to use your cardiods, you can still set up the CA-14's on the stand going into your R-05.