What is your budget and how much power do you need?
Your daily usage will determine how much solar power you need. And your group 27 batteries are probably 90-100 Ah each giving you around 200 Ah of power. 100 Ah available.
A rough rule of thumb is 1Ah of battery capacity will need 1 watt of solar. So you would be looking at 200 Watts of solar.
You could get two 100 watt "12 volt" panels (wired in parallel) with a good PWM controller. This would be your least expensive option.
Or you can use the same two 100 watt panels wired in series to a MPPT charge controller. This will be a bit more money but would probably benefit you as the prewired units don't use heavy gauge wire. So you would get less voltage loss by running high voltage to the controller.
Or you could get a single high voltage panel (around 260 watts) and an MPPT controller. These panels are large though so measure and make sure you have enough clean roof real estate to mount it.
Lots of different options!
Direct link to Handy Bob.
Edit...BentB's link is actually a good summary of HandyBob's main points without all the extra ranting! Cheers