I have recommended solarblvd.com in the past for portable panels. However, I see they closed shop earlier this summer.
In looking at the spec sheet they do not give any information on the included solar controller nor the gauge of the wire used. If you wanted such a panel you would need to purchase the 200 watt model to charge dual six batteries.
Solarland is a US made product. The panel appears to be a suitable product. I would recommend replacing their solar controller with brands such as MorningStar, Victron, Sun, et.al. Remember the solar controller goes next to the battery, not mounted on the back of the panel.