WHAT ARE THESE ACRONYMS?

I would choose VSG, RNY, or DS. Anything BUT the band!!!  Also, what is Band over band?

Its a type of revision for RNY patients whose pouch has stretched.  They get an adjustable band placed over the pouch to return a feeling of restriction.

What is an "RNY"

RnY is the abbreviation for the real name of gastric bypass.  Rouen Y (or something similar..too lazy to look it up right now).  VSG (Vertical Sleeve Gastrectomy) commonly called "sleeve".  DS = Duodenal Switch.

All types of WLS.. all with their advantages and disadvantages.

Re:  your second question "what is band over band".. I think you are meaning to ask what is band over bypass.  

Some RnY patients choose to have a band placed over their stomach.  Reasons why are varied and it would probably be better for a BoB (band over bypass) person to explain why they chose to have it done.