I have a basic cheap offset smoker, but I am putting a budget together to see about getting a decent insulated smoker that I can compete with.
As you see on this forum, if you ask what kind of smoker you should use you will get a million different answers. Most, however, will agree that the cheap offsets you find at a big box store are a worst case scenario. The thin metal, poor seals, and proximity of the firebox to the meat causes all sorts of control problems.
Larger offsets (Lang, Klose, Yoder, Jambo, etc.) are a different story, but a different price tag too.
You don't need to drop big bucks, but you will have to spend more than you would on the big box store products. Insulated cookers (Humphreys, Backwoods, Deep South, Stumps, etc.) are quite nice, but a few Weber Smokey Mountains or drums would also work. Gateway drums seem to be current fashionable favorite, and a lot of competing drums are popping up now.
You will see people debate stick burners, charcoal, and pellet cookers in many threads here - no need to repeat that here. You should pick a cooker based on your cooking style (low and slow, hot and fast, electronic controls or manual) and your budget.
Whatever you pick, practice, practice, practice. Almost any cooker can win, but you have to know your equipment. What are the hot spots? How sensitive is it to rain, wind, or snow? How do you adjust for those elements? Does humid or dry air make a difference? Even identical cookers made by the same company could have slight differences in performance. Learn those differences and adapt your cooking program to suit them.
KCBS events aren't going to be that different from what you are used to, so don't be intimated. Jump in and try it. It's all a learning process. Best advice I ever got was take a class a year. At the beginning you will learn a lot. Later on, classes help you stay connected with what others are doing and thinking. BBQ, like everything else, has trends that change over time and you need to be aware of them.