Looking good there, looks like you've got the hang of it. For increased capacity, here's something I tried last weekend when I needed to smoke 3 racks of ribs at the weekend as I had a few people coming over. I usually do 2 racks cut in half to try different rubs and I've used a toast rack or similar to keep them vertical. 6 x 1/2 racks was too much for that so I got the rack out of an ikea roasting tray and did two flat layers. It worked pretty well, I swapped them top to bottom half way through but it gave me more space in my 22" kettle.
This is the type of rack; it has good stable feet:
After I got the hang of ribs I tried pork shoulder. I don't have a lot of good butchers nearby so I was using Lidl boneless shoulder roasts, last weekend I used some Sainsbury's ones that were fine. I take the elastic net off, remove the skin, add rub, and put the net back on as they are a ragged lump. I've used 3-4lb chunks but next I'll try one of the 6-7lb ones I think. There's plenty of info on here about pork shoulders, just cook to an internal temp, not time. Another good thing to try is chicken, either spatchcocked or vertical - it stays really moist either way.