You have received great advice and suggestions in the responses so far. I'll just add my two bits worth:
I seem to recall from Pianotuna that the ball park ratio (Solar to battery) is 50 to 160 Watts of solar per 100 AH of battery. This would indicate that your 100 Watt panel is minimal and 200 hundred Watts would not be over the fence but right in there. The higher wattage range charge faster and will probably allow you to reach an equalizing voltage.
We run 484 Watts into 420 AH (4 GCs) and usually find it adequate. We are heavier users of power than you are though, often running the TV and Satellite receiver for a couple of hours daily and the microwave for short spurts once in a while. We don't equalize with solar.
If money isn't a big factor, double or even treble up. Make sure of course that the wiring and controller are adequate for the increased current.
OR, try the 100 watt panel on its own and see how you go. Remember though that chronic under charging is death to batteries.
Follow some of BLF13 solar threads; he has tone a lot of trials and testing and has lots of numbers.
