Tuvok,
You really have two ways to go.
1. Buy an 8.5', lightweight, non-slide, short bed truck camper in the 1800 to 2200 pound range, wet, that has enough amenities to satisfy your needs. This way you have plenty of stock capacity (tongue weight) available for your BBQ trailer, even with an extension. The reason I say this as towing a BBQ trailer to cook-offs, or beach camping are not winter modes, so you will spend most of your time out of doors.
2. Buy a larger and heavier TC that has enough amenities to satisfy your needs. This would require, as outlined above, many suspension, tire/wheel, and capacity upgrades. Again, for sand, 19.5's are out. There are some 17" and 18" tires now in the 3860-4100 pound capy area that have enough sidewall to air down enough for the beach.
I will council, "always move in the direction of having too much truck and not enough camper".
jefe