Kyocera, Shell (Siemens), and BP are all good brands.
At $474 plus shipping, the 120W Kyocera KC-120 gives about the lowest cost per watt, and 20-30AH/day IF you have a 56" long stretch of roof to mount it on.
The 110W Shell SM-110 is a little more costly at $535, gives only a little less, but is only 52" long.
BP's 120W SX-120 is over 57" and a bit more expensive yet.
You'll also need to buy mounts, cabling, and a charge controller. RV Power Products' Solor Boost 2000E MPPT controller is popular and about $206.
Northern Arizona Wind & Sun