I also question what you have as group 27/29 are 12volt starting batteries not the normal deep cycle house batteries. Perhaps your looking at the starter batteries? Most modern diesels have 2 starter batteries 12 volt for the engine and 4 gc2 “golf cart” 6 volt batteries ( wired to be 12 volts ) Costco has gc2 6 volts in many locations and would be a good choice I believe
If you never dry camp anything will work as a house battery but won’t as last long.
Also you list a owning a 2000 Monaco but are asking about your Tour?