The question was too broad. Catering, competition, family?? You need to refine your question and in your mind how many ribs to you want to cook? Cooking ribs for 200 (catering)requires a different cooker than cooking a rack or two. Price is also a factor. UDS is the least expensive for a home cooker and a Big Green Egg is the top on the price dept. Do you want a pellet pooper or a WSM style. I've had a lot over the years and started with a WSM, got an off-set that really upped my game and gave a different flavor to the food, cooked on lots of pellet poopers but they don't have the same flavor profile as real wood. Have a large off-set on a trailer for catering. You pays your money and take a pick. I suggest you find a competition close by and talk to all the teams about their opinions before you drop a lot of money. Start with a WSM or a UDS because they will last a lifetime and are useful even if you end up needing more space and get into catering.