You already know you need tall fences if you want to keep turkeys in. I don't think sheep & goat comes that tall, but if it does I think it might be awfully dear. Turkeys need a fence they cannot (or think they cannot) perch on. Floppy is best and from my experience, taller than mine. I got the six ft welded wire. Don't do that. Get woven if you're keeping goats. My turkeys broke the welds, sitting on it; think what your goats would do.
Not all turkeys will, but all healthy turkeys can fly over a six ft fence. Whether they choose to is another matter. At any rate, pick a height. I'm pretty sure they can do more than that. You have to compromise between your desire to cantain the birds and your willingness to spend the money/do the work. You'd probably be fine with six.
My mistake was that I tarped the run fence over winter to keep wind and drifts down. They saw the tarp as a solid edge and proceded to roost right on the wire, preferring that to sleeping in their shed. As long as you don't do that, you should be fine. Put a gate in, though, because the occasional one likely will fly out.
Don't run the posts all the way to the top. Leave the last couple of feet unsupported. From what I've read, keeping the fence a bit floppy helps keep goats enclosed as well.
