Alex Kosmicki wrote:
I was hoping for some input as to if the two posts would hold up to high tensile woven wire or if they needed some bracing.
The posts will hold fine. It is their connection with the ground that is the challenge. When you sink your post holes, cut a trench at a 90 degree angle to the run of the fence wire. Bury a log that touches (tangent) to the post in the trench at right angle as deep as possible so the post is supported low in the ground. As for the top of the arch there are numerous ways to secure the two posts using timber framing techniques. A bit of carpentry work will need to be done, but a mortice and tenon joint will hold the two together and give it a more organic look.
Sounds like a fun project. Here is another thought. If you are several years out from completion of this project, why not grow a couple of osage trees in place! As the samplings come up train them to bend in the shape you want; and train them to intertwine at the tops. Once the roots are established and the tops have merged you can girdle the trees so they stop growing or let them continue to develop character. Either way those gate post are going no where for many decades, as osage is slow to decompose, living or cut.