I dont know about brands of encoders, but I made the mistake of getting single ended encoders and not differential encoders. You cant run very long lenths of control cable for single ended ones.
Another brand of driver is Rutex. These have a much higher amperage handling capacity. I guess it depends on the amperage of your servos that will determine what you need.
Have a look here for other types
http://www.cnczone.com/forums/forumd...?s=&forumid=30
I plan to make up a comparisom chart in the future.