The pair of group 27 deep cycles are fine for the house batteries. I had to replace my 7 year old house batteries this week. Personally, I went with a pair of Interstate Golf Cart 6v batteries wired in series. However, that was just a personal choice, and a pair of 12v deep cycle batteries wired in parallel is fine.
Do not go with a deep cycle for the chassis battery. Stay with a starting battery.
Put a
Trik-L-Start on. I ran my chassis battery down 2 or 3 times in 3 years before it died. When I replaced it, I installed a Trik-L-Start and have never had another problem in the 4 years since.
To install, find the relay that connects the two sets of batteries together. The Trik-L-Start has 3 wires. Wire one is to the chassis battery side of the relay. Wire two is to the house battery side of the relay. Wire three is to vehicle ground. Simple. Works.