This question comes up about once a month.
Do a search on the cookers you are interested in and I am sure you will find all the info you need. Rebel, Superior and Assasin smokers are all made by the same shop. Different names and options.
All are great smokers and have their attributes. All depends on your usage, price, size requirements, options, cooking method, etc. I know BWS and Stump's have forums with Buy/Sell features as well as this site if you are looking for a used one.