I know what you're saying about multi band compressors. I've used them in protools but haven't seen many for live situations. I can't speak out of experience but I have some ideas that may help. You can check out a:
-mastering processor: TC Finalizer, DBX Quantum they both have multi band compression but I don't know how well they would integrate into a live setting.
-Channel Strips: Presonus Eureka, Focusrite trakmaster, penta or twintrakpro
I haven't used any of these but they claim to have a compressor and EQ. I don't know how they implement them and if they can be used as a multiband compressor. From what I've read multi-band compressors are being marketed as mastering processors now.
If this helps I'd like to hear about your implementation of it.