Randy,
If you go with 4 - Trojan T-105's each battery has a 225 amp hour rating. 4 wired in a series/ parallel configuration will give you 450 amp hours at 12 volts. The 6 volt Trojan batteries are true deep cycle golf cart batteries which have very thick plates which can be used down to 50 percent capacity and recharged over many more cycles than the 12 volt "deep cycle" marine/rv batteries.
Depending on how much boondocking you plan on doing should determine what you use. An occasional dock at Wally World, 2 - 12 volts would do....sitting for 2 to 3 days the 4 - 6 volts are better suited.
See link for for info on t - 105s
http://www.trojanbattery.com/product/t-105/