FWIW, Matt, I have a combination t-track/miter track in my table. But, I use it only for "store-bought" feather boards that are designed to fit into one or the other, but don't have good clamping surfaces. Even for that, the use is, at best, occasional. Although I built a sled for use with a miter track some years back, I don't use it. It's far easier to simply guide against the fence.
On a router table, the only "squareness" that matters is the face of the fence, and the axis of the router, to the table surface.
So, unless you have a specific requirement, consider skipping the miter track for now. You can always add it later if you feel the need.