Would it be better to get financing directly through the dealership or would it be better to deal with a broker to line up financing and then go to the dealership? My wife and I both have good credit and own our home located in Florida.
Your best bet is to research all your options: banks, broker, credit unions, on-line, and thru the dealer. I'm not in the OP's area, and didn't buy a 5th wheel, but I got a pretty good rate thru the dealer with Bank of the West after letting them know I would only be interested if they were competitive since I had excellent credit and other options.
Frankly, most of the financing sources I explored seemed more interested in long-term 10 or even 15-year loans with little or nothing down. I'm sure many dealers have links to similar deals, which undoubtedly pay a higher commission, but they may also have pretty good rates for those looking for shorter loans with larger down payments and lower interest rates, although they may not do as much to promote those loans.
You'll only know you're getting a good deal if you know what the alternatives are.