Use the locking polytape clip even if you are using polywire. It is subject to fewer tangles and the locking feature is handy. After each pulse the capacitor stores up electrons for the next pulse. Your fence, regardless of the animal being controlled, does not need more than 5,000 volts. Commonly the best energizers will deliver 4,500 to 7,000 volts.
Energizers are available that produce even higher voltage.
The portability of your fences can be maintained by using a DC energizer with deep cycle batteries. A solar panel can eliminate the need for replacing batteries. Some people like Fords. Some like Chevrolets. The same can be said of fencing materials.