For chain link and barbed wire, I would agree with Glockmann99. If you are going to cut alot of wire, a multi-tool will not be a very wise choice.
I usually use Wiss pliers, heavy wire cutters, or small bolt cutters. Your hands will get very tired very quickly using a multi-tool. They do not have enough length on the handle to give you leverage.
As far as cutters in multi-tools the Gerber wins. I have a Supertool, Supertool 200, Wave, Swisstool, SOG powerpliers, and the Legend. The Legend has a very good wire cutter, but it is a general purpose tool.
Daniel