Welcome to the Forum!
I will second an earlier post, get the most truck you can afford if you will be going the TC route, especially since you'll be using it for extended trips.
Our first TC was an 8' Lance Lite on an f250. We used it while CG hosting at a National Monument site in New Mexico. The two of us couldn't get dressed at the same time and one of our fellow hosts told my wife one day "Honey you have a one butt kitchen!"
We upgraded to our present truck, an F350 Dually, and upgraded the TC to a Lance 981 with a slide. It was like night and day and we really enjoyed it.
About two years ago we decided we wanted the space that a TT would provide so we traded the Lance on a 28' travel trailer. I still enjoy it for trips of a week or more IF we plan to stay somewhere where it will fit. The down side is that there are lots of neat places around here where it's simply too big to get into the spots designed in the 1930's. So we were fortunate enough to find an older non-slide Lance 880 last July. It's a 10'9" TC with plenty of room for two. Now we have the best of both worlds.
The moral to this story is that our truck will accommodate pretty much anything that we want to camp with. We could easily pull a 5'er if so inclined.