I just had a question. I have a Goal Zero Yeti 400 Solar Generator.link Im looking to buy a 100 watt solar panel for it. I've heard that Renogy makes good ones. Im looking at the 100 watt foldable suitcase link. I know I need an adapter in order to hook up a non Goal Zero panel to the Yeti Solar Generator. My questions are: On the solar Panel; do I need to get one with the controller? or no? And considering that this solar panel will not be mounted on my car, and that space is at a premium, is this the best "bang for your buck" option? Any other advice would be greatly appreciated. thanks -Xan