I speak from experience, invest in a electric charger and put you up a couple strands no matter what type fence you go with. You will have far fewer headaches.
First, are you planning on keeping the billy intact as a buck and keeping the buck and doe together? If so, you risk the chance of having them breed at will, never knowing when she'll kid. Not to mention that the buck will try to breed with any doelings you may get as soon as he can, which is not a good idea. A good plan would be to house them separately and have separate pens/pastures, which, of course, means you'll need to get friends for each. If you plan to wether the male, that's a better plan if you intend to keep them together. We put field fencing up for our goats; however, learned quickly that it wasn't sufficient enough. I ended up running 2 electric wires, 1 about 4-6" off the ground and another 4 ft high. This kept the little goats from crawling under the fence and the bigger ones from jumping over.
