We were in your exact shoes three years ago (1 1/2 year old and 1/2 ton truck) and here is my take:
-You are absolutely doing the right thing reading these boards and anything else you can read. Don't listen to the salespeople. You probably know more about towing at this point than they do.
-We did plenty of research ahead of time and I never bought into the "rent/buy used/buy your next trailer" stuff. It probably helped that I have camped since I was six years old (I'm 37 now) and we had a popup for many of those years.
-We bought a new rear living floorplan and towed it for two seasons with our 2013 1/2 ton Silverado. It is the trailer in my sig and weighs 7,500 pounds loaded and is about 32 feet from ball to bumper.
-We still have the same trailer, but did move up to a 2500 truck. It really came down to the payload. We went from 1,500 to 3,000 and can now load a rick of firewood and hitch up without thinking twice.
-We have had as many as two extra adults and three extra kids spend as many as three nights in our trailer, and it worked out. It's not ideal, but it works. Having just one kid, who is now four years old, it's rare that we have a lot of kids staying with us and we prefer the huge living area over the big rear bunk room.
-We can access our bathroom and front bedroom with our rear slides in and it is great. If you plan on taking long road trips, I don't think this can be discounted. Also consider the fact that many center kitchen floorplans have a slide that eats into your outdoor living/awning space.
-Best of luck to you all and safe travels!