We elected to go with a portable panel for our Bambi for the exact reasons you stated. I like the Zamp panels but the price seemed prohibitive. I picked up this 150W unit which included a controller (
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1). It came with alligator clips to attach to the battery.
There is nothing proprietary about the Zamp connector. They are an off the shelf 2 conductor SAE connector available at any automotive parts store. I picked one up at my local Napa store, cut the alligator clips off the panel and soldered the SAE connector onto the wire. Easy 10 minute or less job. The connectors often come in pairs wired together like this one (
https://www.amazon.com/CES-Gauge-Qui...+Pin+Connector). Just cut the wires in half, solder the appropriate one to your panel and throw the other half away,