I have the same problem (wanting a nice big trailer with all the features to be pulled by my Edge) however that said there are a couple of hybrid travel trailers that just fit under the 3500lbs:
* Kodiak Expandable 160 - 2862 lbs
*Starcraft Sport Expandable 175RK - 3500lbs
You will not find many travel trailers hybrid or normal over 17 feet long that will be under the towing capacity.