What are you going to be using to tow? Do you already have a truck? Whatever you decide to use, learn it's SAFE towing limits for your specific model, not just the general numbers published in the advertising.
You said you're going to have 3 adults travelling with you, and potentially more. As far as I know, you can only put a max of 6 people in a truck, and that will get to feeling mighty cramped on a long trip. A fifth wheel will limit you to using a truck to tow. Not necessarily bad if you already have the truck and use the truck for your everyday use as well.
With a travel trailer, you could use a full-size van to tow and people will have plenty of room to stretch out when on the road.
Overall, my advice is not to rush into anything and don't try to get any real helpful info from dealers (RV or truck/car). Salespeople, in my experience, are not usually very knowledgeable about these details. You'll get better answers from the members of this forum, so don't hesitate to ask away! :)
~Rick
ON EDIT: In response to your "easier to set up" comment and that you might be using it on your own, I'd recommend that you include Class C's and possibly some class A's in your search as well. There are C's that have twin beds in the back with the overhead bunk in front. When others travel with you you'll have the dinette & sofa for sleeping as well. Our Class A will easily sleep 7 and has seatbelts for 12 people. Not saying a motorhome is your best solution, but if you're looking at $50k fifth wheels, I think you should at least entertain the idea of a used Class C or Class A in that same price range.
You seem to be concerned about purchasing the wrong RV and having to trade up later. Take your time. We spent over 2 years researching for our "ideal RV", and we believe we have found it. Started looking at hybrids to tow behind the Odyssey minivan and ended up with a 36' motorhome TOWING the Odyssey. But in almost 10 years, we've yet to find a floorplan that we like better. And most of the thanks goes to the fine folks here who helped us make the right decision the first time. Good Luck.
