I couldn't mess with you if we weren't freinds. 
It boils down to what you like, lots of bite,long range, loud voice, babble mouth.
Little bite, short range,just a bark, silent, semi silent.
For a decoy dog to be good, you will spend alot of time with him(or her). So talk to the sellers about what their dogs are like, or what they try to breed for.
They all have good and bad points, and there are many ways to use/hunt them.
My very best decoy dog was no range (100yrds), silent, no nose, and lots of teeth.He is retired now.His main replacement, has med nose, short range (1/4 mile) trails silent, bays hard and fast at the catch,and lots of bite.
He's fixin to bypass the old dogs yote numbers.
I could go on and on about each of my dogs, with the specific traits, but the point is that whatever "type" of dog you like if you hunt them, and train them properly, you will be successful.You will find some of these traits in any of the Curs, and they will change from litter to litter,and pup to pup, within a litter.Thats part of the fun.
I left out size, you need enough to get it done, but to big, and your dogs will over heat fast, and tend to run out of steam.I'm breedin for smaller frames.
CB, I hope this gets you started. 
