I honestly think you would be just fine with a standard jetski trailer. I have a 150gal smoker built on a jetski trailer, and actually had to buy lighter springs for it. Here's a few links for you to think about.
Not right off hand. I can get you one though. Mine is not a reverse flow. It's a center rear feed and the CC faces the rear of the trailer. The FB is between the frame rails. I'm in the process of building a completely different smoker now that's a 250gal RFS. My 150 is actually an oil tank, so it's not as thick as a propane tank. But it is probably around 200lbs by itself.
I used an old jet ski trailer, it is 3''x1/4'' channel iron. I extended the trailer 18'' and moved the axle back to get the tongue weight that I wanted. This is a piece of 25''x3/8" pipe, 48'' cook chamber and 18'' FB, I don't know how much it weighs but it pulls fine and seems to be holding up fine.
I priced out material and parts to build my own trailer. $425 or so for: tires/wheels, hubs, leaf springs, shackles, lights, wire, jack, plug, axle tube, coupler assembly, tire fenders, etc. I was thinking I would be around $200 for the steel: c channel or tube for the frame and expanded for the floor plus some other material for light brackets. So I knew I would be around 625 or so at least. I called a local trailer builder/weld shop and they quoted me $650 to build a trailer for me and to mount my smoker to it. I'm not sure where you are located, but this shop is in Union, Missouri. The trailer turned out great and they stuck with their quoted price the whole time.
I was going to get all the parts as well. But they had the small trailer for 267. Which was less than the parts I needed. So when I got there they had 2 of the same trailers marked down to 129 as the where changing vendors and packaging. Plus I had a 20.00 off coupon. They had a 4x8 folding trailer for 260. The same reason. I was going to get that before I found the chaperone.
My 4 x 8 trailer was $490 total for all the box tubing, steel, axle, fenders and 1/8 diamond plate floor, lights, and railing. The wheels & used tires I'd gotten for free so easily another $120?? The best part of it is that it is really a custom and perfect fit for my firebox and tank. Nice that you can just tow it home...finished
Make no mistake, there ain't no powder in this Puff ! And... I'm not really a crazy person but I play one in real life
I made my own, but it was mainly because I don't trust people to grease their bearings properly. I got all my supplies from AA wheel in N. Kansas City. I think for dual 3500lb axles, brakes, suspension, and tires I paid around 700. I did my frame out of 4" channel (much to the chagrin of the 'tubers' on here and FB) and that got pricey....but my trailer now doubles as a weapon, so Im happy.
On a note about tires, I found out an old friend from Jr. high is now the distributer for AA wheel tires and wheels and Croft trailer in this area. He hinted I can buy direct from him for around $25 for a tire and rim set. I plan to take him to lunch and see if he will do random orders for our illustrious community.