Ellie, here are a couple of links you might find helpful. In the first picture, the yellow connector is an Anderson connector.
http://community.fmca.com/blog/805/entry-1586-diy-rv-solar-install/
Here is the cable/connector I used to connect portable to battery:
http://community.fmca.com/blog/805/entry-1586-diy-rv-solar-install/
In spite of the nay sayers, portable looks like a solution for you. I just got started with portable because I wanted to learn before doing anything permanent and most of my campsites have been in the shade. I have the Renogy 100W suitcase portable and the alligator clip cable at the end of it already had Anderson connectors, but using them was a hassle so I switched to the cables above for a hassle-free quick connect. Ideally, the controller (mounted on the back of the panel) should be close to the battery bank connected with a heavier cable to minimize loss. I plan to remove my controller from the panel and mount it near the batteries instead, then get longer cables from the panel to the controller also using the Anderson connector so I can get my panel(s) out to the sun.
Do you have the GoPower portable? That 7-pin adapter is something I looked at but realize my trailer has batteries at the front and converter charger in the rear and that would be a really long run, so I went with something to get my solar right to the batteries. The 7-pin adapter from my research comes with an Anderson connector so you will need one on the end of the cable coming from your solar. But the connector cable I used should be more effective, and given your situation of not needing longer cables, should be all you need to do for ease of connection.
The 2 wire adapter someone posted is a type of connector that works well also.