Not sure if it’s the same in your area but there are fall and spring boat shows in the south. Some actually on the water so test rides are possible. Most manufacturers have “boat show” prices that are discounted as well as better financing deals (if needed). Usually insurance companies are there with “boat show” discounts on policies as well as Sea Tow or Tow Boat US also. That sucks about the dealer holding your down payment but if that’s the way they operate you may be dodging problems after the purchase anyway. Lund makes a really nice aluminum hull. I don’t think you can go wrong there. What are the most common styles and manufacturers on your body of water? Perhaps a couple of Saturdays at the boat launch to watch, learn, and chat up the owners may help with your purchase decision.