Let us know how it goes. My first pit was a New Braunfels Hondo I bought in the early 2000s. Probably 3/16" thick. It was frustrating to use and I mostly put it to use as a grill. But I really had no idea what I was doing. From there, I moved through a Pit Barrel (briefly) to a WSM, which I love and am keeping for those times when I'm too busy to tend a fire or just want some sleep. I sing the WSM's praises whenever possible, and it's thin metal. But it's well-designed, easy to use, and I've put out some exceptional food on it.
Incidentally, I gave the Hondo to a friend of mine and he's still using it over 20 years after I bought it. He'll burn out the firebox soon enough, but it's gotten him into smoking food and, to my benefit, he's keeping me supplied with wood from some rural property he owns as long as I go out and help him cut it on occasion.
3/16" steel may be fine in that vertical design, and there's only one way to find out. In my case though, I wanted to buy once/cry once and spent about $650 more than I would have spent on that Old Country G2 at Academy. The G2 is a beast, but I don't regret the wait and a little extra money to get get the smoker I got, which is a monster for its size and spec'd out like pits costing even more. I have no worries about its longevity as long as I oil it up periodically and keep it under cover. And so far, the extra-thick gauge of steel has made the learning curve not so steep with my first two cooks going really smoothly.
But what I learned in the last day is that vertical offsets are not all that common, and when you do find them from custom builders, they ain't cheap. Keep us posted.