Unless you mean wheel size, there isn't too much of a difference in bmx bike size.
The two things that change are top tube length and handlebar height.
I think that top tube lengths run between 20'' and 21'', but I'm not quite sure, I don't ride bmx too often (I ride dj/street mtb)
High rise bars seem to be pretty popular, which is a lot of personal preference, but there's less reach for taller riders when they ride with high rise bars.
Here's the part about how it applies to you:
5'11'' is big-ish. Id probably go with a longer top tube length if given a choice, (closer to 21'') Also, you're probably gonna want high rise bars.
a good examples of this kinda bike are the kink bikes on danscomp.