I would suggest you forego the insulated or heavier version. I'm not familiar with Shirley, but I do have a horiz offset stick burner and a vertical stickburner in SoCal, both uninsulated. I've never had an issue using them here nor, in prior moves, in Texas or in England in snow, sleet, or cold rain.
I realize my views likely don't match most Brethren's, but IMHO insulating a stickburner is unnecessary and highly overrated (unless you live up north in a really cold climate). On the downside it adds a lot of weight if you ever want to move it, whether on a trailer or just around the back yard. And the extra cost.
Plus, frankly I've just never seen the point of deciding to buy a stickburner and then doing everything possible to minimize the amount of sticks you burn, which seems to be how many folks approach it. If you have decided you want to cook with smoke from wood logs, and you are spending a lot of money on a smoker with which to do so, I humbly suggest you plan to burn some wood! Just my POV.
