Jumping in a bit late here, I think you would be fine carrying a bit more than a tc650, especially if you will not be doing any real wheeling. I seriously considered upgrading to the 850SC that is on the forum for sale right now- but alas, i have a camper that is just fine.
A great condition used camper can help with alot of unknown questions about which brand is perfect and all the other details that get lost when the price is right.
With a 6foot bed you will be great with the added length of the SC, tailgate down.
I would, without question, add E-rated tires to your airbag setup to handle the additional weight.
Shocks are more of a personal preference, they dont help carry weight, they absorb the rebound of your springs going over bumps. You could try stock and go from there as needed.
Sway bar might be a bit redundant with airbags on unless your bags are pneumatically linked. Add air to bags and the suspension stiffens lessening sway.