Have been smoking for about four years, use the 18" Weber Smokey Mountain smoker; a terrific unit, first class workmanship. A small bit of advice - use the standard, cheap Weber briquettes or whatever equivalent you have in the UK. Fancy charcoal burns unevenly.
https://www.weber.com/US/en/charcoal/smokey-mountain/smokey-mountain-cooker-smoker-18/721001.html
Three weeks ago I became a certified barbecue judge. My first judging gig is in 2 weeks.