Been awhile since I posted here, but I've been asking myself this same question. I've considered a Horizon or Old Country, but my budget can allow for something like a Shirley 24 x 36, so I just emailed Shirley to see what the lead time is right now and how much shipping would be.
I've got a Weber kettle and a Grilla Silverbac, both of which I love, but for beef and pork ribs, I really have found that I like a wood-fired flavor. I have played around with that on the Weber, to the extent I can, and it's just better to me. The Grilla has so many other uses that I'm not worried about keeping it and an offset. The weber may go eventually but one extra grill isn't the worst problem in the world.
I do have a friend who can weld really well, so I may look into that DIY kit just posted, seems intriguing.