Having owned both travel trailers and fifth wheel, I will say both have their advantages and disadvantages. Towing with a one ton will be flawless for either type of trailer. As you stated, the difference is where the storage is located.
We switched from TT to 5er after a lifetime of TT's. When we had the TT's I had a contractor's shell on the bed of the truck. It had a ladder rack so we could easily carry a canoe and it had side panels the entire length of the shell (8 feet long) with 2 shelves on each side. This provided massive amounts of storage, and did not even touch the floor of the bed of the truck.
So everything for the canoe was kept on one side, including extra lumber for leveling the trailer and set-up. The bed of the truck was used for a 7 foot step ladder, the sewer tote, an extra 35 gallon water tank (for transporting water when we had no water hook-ups), an air compressor, and a number of other items. I also kept my tools in the side panels, everything from an electric drill to paint brushes. .
Those items were seldom, if ever removed from the truck, so everywhere the truck went, all that stuff went with the truck. At home, I had a large utility trailer so I never had to remove the shell if I wanted to haul large items (like refrigerators, washing machines, building materials, or even dirt or yard bedding mulch.
When we got the fifth wheel, things changed immediately. Of course the shell went! That also meant the canoe could not go with us any more. But, by now, the kids are all grown and don't travel with us any more, and my wife and I are getting older anyway. The canoe was just becoming too much work to transport. So all the paraphernalia for the canoe was now left behind. And all that storage on the side panels was gone too.
But, the fifth wheel provided enough storage that everything I originally carried in the truck fit in the trailer storage areas, except the canoe stuff. It took a different mind set for the fifth wheel. I still use the bed of the truck for the sewer tote, a (4 foot) ladder now, sewer hoses, and extra lumber for leveling, portable dog fences, and other stuff. The bed of the truck has a cover, keeping everything out of weather and out of sight, discouraging theft.
Our style of camping changed over the years too, which made the fifth wheel more practical than the TT's. We transitioned from week-end warriors and 2 week a year vacationers to long-timers. We now are away from the house for 2 to 5 months at a time, return home for a month and take off again. We've currently been a camp host at a State Historic Site in Louisiana for the last 2 years, returning home about ever 4 to 5 months for a month.
That changed everything as far as our gear needed, how we use it, and where we store it. Considering we are stationary for 4 or 5 months, we are able to keep everything out of the truck.
The bottom line is, only you can determine which set-up will work best for you. It does depend upon your camping style, and what you do when you camp. If you are planning on work-camping, those items you bring with you will be different than if you are truly traveling as a life-long extended vacation.
Which every way you decide to go, I STRONGLY advise you purchase the truck and the trailer now.... as soon as possible, and use it extensively over the next couple years. It doesn't matter which one you select, you will adjust to it, learn what items you truly will need, and keep unnecessary items at the GoodWill store!
You will also need to customize your camper, it will have repairs (warranty and other), and you will be making changes, moving thing around, determining what items you really need and what items are unnecessary after all, stocking items, and purging items until you find the happy balance! It takes time to figure that out.
Toy haulers are a fantastic compromise, and I vote for that route. For full timing, Fifth Wheels come in second in my opinion, especially if you no longer have a home base, and even more if you park long-term somewhere. A travel trailer is ideal for "travel", shorter term visits, and if you have a home base to return to. But, this is not a hard and fast rule, it's just my preference. Full-timers are very successful in travel trailers too. It's all a matter of how you adapt.
That is also a reason you need at least a solid year of different camping experiences before hitting the road full time. You need to learn how to use your camper in extreme heat, extreme cold, in severe rains, wind, and during the pleasant days as well. This all takes planning and experience helps before you have to do it with no other options available.
That the best advise I can give you. The specifics are truly based upon your personal lifestyle, needs, desires, and how adaptable you are to the logistics of your set-up.
