HC-110 is ok with most films but I don't think it's the best choice for anything...(posted 8091 days ago)For low light situation, John Hicks suggested a few months ago about pushing Delta 400 to EI 800 in Ilfosol-S. I strongly recommend to find that discussion and consider test shooting before the real wedding. I think ID-11 1+1 would also be a good candidate for this, but I'd switch to Microphen (stock) if you need further push. TMZ is great but I think it'll be too grainy for the purpose. I suppose you are using 35mm (as TMZ doesn't come in medium format) so use something like 35mm f/2.0 on Konica Hexar or rangefinder cameras and move around. Available light is in many aspects harder than using a flash.
Also, I find myself draining films quickly when shooting Hexar without flash because people do not notice me photographing and it's really easy to shoot a lot with it. Bring a lot of films...