Good luck on the trailer.
I also have a 28' double slide Sunnybrook, and we love it. Quality & operation is good.
Would certainly buy Sunnybrook again. Also, their reputation is a reason we looked at them.
Theres others that are good as well, but going w/ Sb, nash, alpenlite, and a few others, you basically almost cant go wrong, as long as you get a decent deal.
One thing to pay attention to is the drain pipes. You want them to be inside the insulated part of the rig, not exposed.
Also you want shocks & suspension, not rigid mounted axles.
Make sure you get 16" wheels.
Another tip is to make sure that the dealer gets the ride height & bed clearance right before you drive off the lot, and make them pay for raising the axles jake plates, or whatever. Dont let them charge you for it, thats a common little "extra fee" they like to spring on the customer. Most experienced buyers make sure all that is covered in the deal.