All right, for starters, you're already doing the right thing by not listening to the trailer sales guys. They are just there to make a sale, and I wouldn't trust them further than I can throw them.
Like BA says, make sure you have a tranny cooler on whatever you're towing with!
Your hybrid will probably weigh over 4000lbs by the time you add water, propane, gear, food, "stuff" (beer

). The dryweight will also not include any extra options you may add to the trailer. As it is never pleasant for both the driver and the truck to tow near the limit, I would stick with the Toyota. Get the Hitchshop to add a towbar and a 7 way plug, and you should be good to go. If you can, don't buy the weight distributing hitch / anti-sway / brake controller from the RV dealer, they'll overcharge and undersell you; that gear is a whole other subject.
Now, instead of all the sales literature and commercials, what really determines what you can tow is on the sticker on the driver's door jamb. You have three major weight limits: GVWR (gross vehicle weight rating), rear GAWR (gross axle weight rating) and front GAWR. Those are the most important. There is also the GCVWR, which is the combined weight of your truck, you, your family, your stuff, and your loaded trailer. And don't forget to look up the published "tow" rating for your
particular configuration of truck; this should be in your manual somewhere.
If you can, the best thing to do is to figure out how much your truck weighs with you, the wife and any family members and all your "stuff" like food, beverages, and firewood. You may be surprised. Subtract that amount from your GVWR to make sure if you have any room left for the trailer tongue weight. I suspect your hitch dryweight will become 400lb+ once you have water and propane tanks on board.
Having said all that, I think the Toyota should be capable of doing the job safely, but double check the numbers to make sure. The 19' length is OK. Remember, you're buying a trailer for enjoyment, and not to get extra stress from a bad setup.
Edit: In an attempt to be more clear.