Then I recommend 2*100 Watt panels on the roof. For the lowest possible price, you probably can't beat this 'WindyCity' Kit:
http://www.ebay.com/itm/COMPLETE-KIT...d/251419849809
But it is polycrystalline, which requires slightly more size and weight to achieve the same rating as equivalent mono panels.
Among TM owners, WindyCity and Renogy seem to be the most popular EBay sellers. If you buy a Renogy kit, be sure to get the upgraded controller (their cheapest controller runs positive-ground ONLY, while RVs, cars, and boats are almost universally built negative-ground.) Although I'm recommending a WIndyCity kit, I personally bought Renogy, and it's been great. Outside of EBay, Arizona Wind and Sun has a great product lineup, equally good prices, and also a superb set of informational web pages. They've also got a good forum.
If you stay with only a single battery, calculate your AH requires carefully to make sure that you can stay above 50% charge while enjoying your outing. If you can do that, then a single panel in the 120-130W range is probably sufficient.