Hi Joelyn,
I'd suggest two "12 volt" panels in series.
If you just want maintenance between golfing trips, it may be possible to just direct connect them to the batteries. What size in amp-hours is each of the six volt batteries?
If you want more rapid recharging, then two 60 watt panels in series and a charge controller meant for 36 volts would be needed.
Regards, Don
My ride is a 28 foot Class C, 256 watts solar, 556 amp-hours of Telcom jars, 3000 watt Magnum hybrid inverter, Sola Basic Autoformer, Microair Easy Start.