Hey, Brands are not really that important… your gonna wanna decide what is easier and what fits your application. 

Steel - Pros - Easily fixable (welder, grinder, etc)
                - Very trong

       - Cons - Heavy
                - Can oxidize (rust, if near salt water)

Aluminium - Pros - Lightweight (good for racing and jumping)
                         - Doesn't rust

               - Cons - Can be harder to fix
                         - can bend easier (if not the right thickness)

Other then that there are a few other things to remember, if going for Aluminium make sure that it is at least 0.25″ thick.  Other then that you can base a lot of it off of visual appearance and preference. Shop around though and find something you like, and something in the right price range.. there are alot of options if ordering out of the US….