Since this is your truck start battery only I would think you would not need to consider any of the RV COACH BATTERY requirements.  The purpose of the truck start battery in my setup is to start the truck and run all of the truck electrical requirements.  I would install whatever the current truck manufacturer requires and fits the truck battery holder..    
I also follow an golden rule to NOT mess with the truck battery system for any of the RV Trailer requirements. The truck start battery is what gets me back home..
Having said all of this and not being familiar with the MOTORHOME type RV units the TRUCK START battery may have additional requirements being used in a self contained motorhome type setup...
My experiences is with a pickup type truck towing a RV Trailer. The RV Trailer has a separate RV battery bank setup just for the RV requirements.
Roy Ken