You might consider another direction that has the added benefit of being a negative visual barrier.
Just go to a farm store and buy an electric fence charger. It doesn't have to be expensive to be effective. Then run two strands of yellow poly fence where you want the dogs contained. One at 12" the other at 24". Once they get snapped a time or two they won't go near it.
I've used it on my farm for over 30 years with at least a dozen dogs without a single mishap. It also keeps other dogs and most critters out.
If you take the dogs somewhere else to visit or run you can put up a single strand, not even charge it, and the dogs won't cross it.
The cost for the charger, fence wire, stand-offs, and posts (rebar or such) will run less than $100. Advantages beside the above: no collar necessary, virtually unlimited size (just string the wire), after a month it can be left off. The chance of a breakdown is very, very small.
It also works with pigs but they will try to test the wire every once in a while. Guess the zap is worth it to them. But if they find it is off you will be in for some pig chasing.