We have two sizes of SWAP's at work, but I prefer the smaller size. The ones pictured above, I've used, but the plastic "Keeper" thing feels cheap to me. I like the type like this:
http://www.quickcar.net/tools/tl_wire.html But thats my personal opinion.
Also, as far as the Tiger Wave ones or whatever they're called, I HATE Those type. They never gripped safety wire or cotter pins worth a damn, the knurling on them really helps them grip the wire better. As far as I know, any piece I may somehow nick with the safety wire pliers, I usually end up pulling that piece, then pig tailing and cutting that off. So it doesnt matter to me.
But all in all. Safety wire pliers are nice, but they're not anything you CANT LIVE WITHOUT, a good pair of needlenosed pliers and even your trained hands can twist safety wire just fine. Good luck.
Brandon