47 inches is correct.
12 guage is usually the thicker wire at the bottom and top.
14 is usually the guage of the wire in the field of the fence.
6 inches is perfect and since I estimate and purchase for our company I can tell you I have never heard of 12 inch spacing
Make sure you have your electric fencing well grounded, and have it up and running before you let the goats out in the area, don't let them test your fences and then electrify them.
The best field fences are stretched about 4 inches above the ground, with a barbed wire bottom wire nearly touching the ground and horse wire above, so use long T posts and good strong corners, we have timbers, not 4X4 post, hole dug, post in the ground, fill with dry cement, add water, let set 24 hours, until the next weekend best. H's and then tension wires out of your horse wire. The weakness in your fence will always be the gate or spacing your T posts too far apart. Vicki