Milbar makes the safety wire pliers for Snap On. Not cheap but very nice. They should last you the rest of your life.
Some options to consider are:
Spring return is a very nice option.
Rubber (or silicon) in the jaws to hold onto the safety wire after you cut it.
Being able to switch between left and right hand rotation.
A great place to buy safety wire pliers and other aircraft tools is:
Aircraft Tool Supply Company
P.S. I get no cut on their sales, but have been a very happy customer for over 15 years.