I do not have a boat like you, only kayaks, but know based upon my roof loading kayak experience, your roof loader would be the way I would go.
I am contemplating some changes with our RV situation once the kids have flown the nest. So, TCs are high on my list but that would be only for the wife and me. No way would I consider a TC, even the larges TC, for a family of four adults. And the nicest and largest TCs are VERY heavy. Some going over 5000 lbs. loaded and many 4000 lbs loaded. Also, the class A/B/C would be difficult too for towing a boat trailer if you had to break camp to put-in, take-out. So for me, class A/B/C would be a no.
I feel you are on a track I would take with the TT and roof loaded boat so long as there were rollers and even a hand winch to help with loading.
For what it's worth, you are going to have to compromise on something. Only you can decide what is the easiest compromise for you.
