The article that PT linked said that solar controllers lose a lot of efficiency when trying to reduce panel voltage to 12v for RVs once panel voltage is above about 50v.
I haven't tried to calculate (don't know how) but this might suggest you should go with two controllers from the 100v panel after a Y split to get more total amps to the batteries than going with one controller?
Also go to a 24v battery set and 24v inverter and get 120v AC from that inverter. Use a smaller solar set for your basic 12v needs and don't invert up from 12 to get any 120?