There are many good RV house batteries...
Some folks swear by Trojan (Pricey)
Some by Lifeline AGM's (Even more pricy)
Best Bang for your BUCK.. Sam's Club GC-2 Pairs
Each pair is around 210 amp hours at 12 volts.
NOTE: These are taller than a Group 24 but usually fit the same tray
NOTE: You need TWO of them,, Each one is 1/2 of a 12 volt battery (6V)
Note: When installed the two six volt become a SINGLE 12 volt battery, Treat them as such.
If you have any questions (Example: Can I replace just one) Ask "Can I ____ 1/2 of a 12 volt battery?) and you will have your answer.
Home is where I park it!