You don't really need a long range set up. Work with your dog in the yard and he will still respect it a mile away weather it will work or not. Like a wise man once told me " go cheap or go broke " lol
Beaver are easy to trap for the most part. I'd order a couple 330's and a little lure. Sometimes beaver can be hard to retrieve after being shot. Good luck
All the different kits you can buy will work. The main thing is to make sure you flesh them out well. It's a lot of work. I send mine to usafox.com they do great work.
I use different sounds (vole squeeks, fox pup distress ect). Try hunting deeper in the woods also. I have found that a lot of dogs just won't come in if your hunting fields or cut outs. They feel better closing in with cover.