Well, Flowergirl, I believe that more info is needed before anyone can offer suggestions. For example:
Do you want gasoline, corded electric, or cordless electric?
If gasoline, do want 2- or 4-cycle engine (2-cycle, oil mixed with gas, 4-cycle has oil sump)?
Do you want an edger that has the engine mounted on a base with wheels and you push it with a lawnmower type handle OR do you want one with the engine mounted on top of a shaft (much like a string timmer)?
Do you have a price range in mind?

To get an idea of the styles available, go to Amazon and search on "lawn edgers," pick the style you like best, and let us know. Otherwise, there are just too many variables for anyone to take a guess at.

How much edging do you have to do? What are you currently using?