@ Libertarian,
Since you're in Mt. Pleasant have you looked at Gorilla Fabrications? Great group of guys (and gals) who make some really good smokers.
Disclaimer : They really did a poor job on my food trailer, but the cooker they built me is amazing.
The cooker is a "hog style" smoker with a front-offset firebox, two large racks measuring 4' x 3'. The bottom shelf allows for a massive hog somewhere in the 175-200Lb range, and the top rack (due to clearance) can do about a 125 Lb hog. I've loaded it up with 2 cases of pork butts and 2 cases of briskets and shockingly everything cooks pretty evenly (left to right). Top rack is about 15-20° hotter than the bottom rack, but that's pretty common among all smokers. It also has 2 very strong propane burners (one on the left, one on the right) which allow for cooking with just propane, or propane assist if desired. Usually I'll cook with wood for 4-5 hours and then I'll wrap everything and put on the propane to finish cooking. Once I get things dialed in with the propane I can sleep pretty well knowing the temps won't move very much (usually not more than a few degrees fluctuation).
Just throwing it out there because it is a good cooker for a pretty decent price. The metal is thin but so far I haven't had an issue with keeping solid temps. We had one of the coldest winters on record here in eastern NC last year and I was still smoking every single day and I never worried about temps.
This is the same model of the cooker I have, but the exhaust stacks have rotating dampers on my model.
Overall just throwing this out there as an additional option since these guys are directly in your back yard. Way more actual cooking area than a Lang 60 and, if you ever desired, you can EASILY do multiple hogs / lambs / etc.. on it.
Here's a ~90Lb pig I did last year...it was only my 2nd pig and the appearance kind of sucked, but the food came out really good.
The cost for just the smoker was $1900 I think, so putting it on a trailer would be right at about the same price point as the Lang.