I used 6 foot of beefy #3 chain on my #4 beaver traps...they are big strong animals.

Drowning poles are best if you have the water to drown them in.

Check out this system. I have not used it but it sure looks nice...

http://www.minntrapprod.com/MB-10-Foot-Slide-Wires/productinfo/MB10-SW-6/