There is a brake controller that will work for your tow vehicle with air brakes, though not the Prodigy P2 # 90885. Instead, you need the Hayes Air Actuated Trailer Brake Controller - 1 to 4 Axles - Proportional # HA100400C because the unit is designed specifically to tie into air brakes to control the braking on your trailer.
I've added a link to a video review for you to take a look at, as well as a link to the written manual I strongly recommend checking out. view full answer...
I spoke with Demco about your air line and they stated that the air line fitting has always been the same. The only difference is that some 2019 and newer Spartan chassis came with a larger fitting installed at the factory, so they made a hose # SM6296 to fit the larger inlet. With your Tiffin being a 2008 (2007 chassis) you wouldn't have the larger fitting so you'll be good to go when installing your Air Force One # SM99243. view full answer...
The CE Smith # CE27610 Guide-Ons work well on the back of the boat, but in quick moving water something that's actually self-adjusting like the ARK # AR74FR self-aligning boat trailer loading system which is spring loaded would actively guide your boat to the center of the trailer and would be a better choice. This unit is designed for boats 16-20 feet long, so it'd work perfect for your Cobalt. I've linked you to a product description video featuring the loading system. view full answer...