Unless you have actually weighed that equipment, I suspect you will find another 500 or so pounds appears from things like fuel, R4 tires, tie down chains, binders, the herkin WD hitch, etc. So you are best to assume 6000 lbs of equipment.
An equipment trailer, especially custom made, and worth its salt will weigh more than 2000# for a 7000# 20 footer. That includes a spare and leaves you with 5000# of cargo to be on the ragged edge of the trailers capacity.
I too tow with a half ton GM product. The newer ones have very high tow ratings, like 7-8000+#s so it will likely handle the weight. Just because you buy a 10,000 lb trailer does not mean it will weigh 10,000. It just means that you are not pushing your 7000# trailer to the max and beyond.
I have just purchased a 10,000# trailer for about the same type of cargo weight. See attached pic and look at my recent thread for other folks' input. The 5200# axles put the 3500# version to shame. Also, compare your custom made price to the 3100$ I spent and see if you are gettin more trailer. I feel that I got a good deal without having to chew the salesman down at all.
1) You will overload the 7000# trailer. The 10,000 version is not much more money. This is a safety thing.
2) Always get electric brakes unless you are building a salt water type boat trailer. Very adjustable, dependable, and effective. There is a reason that almost every RV out there uses ebrakes.
3) If a trailer needs four wheels is needs four brakes. Do it. Another safety thing.
4) I made a new number. Get slide in ramps and not flip ups. When your implement hangs off the back the flip ups won't flip up.
5) The marks of a good trailer are one with no angle iron, removable wood boards in the deck, and recessed lights.
I was amazed that some manufacturers actually welded chunks of steel to trap the wooden deck boards in place so that they wouldn't have to screw them down. Great until you need to replace a board.
The brake controller of choice by a large margin in the RV world in the Tekonsha prodigy. I own the tekonsha voyager which is the next step down. It works just fine and has never let me down. The prodigy is a digital one and supposed to be the cat's meow.
I am about a half step ahead of you with a trailer today and a tractor tomorrow. Enjoy and don't feel bad about buying quality equipment when it involves safety.
