If you are considering a custom frame you can safely leave the design in the hands of the builder. You might however consider this, the same 58cm. top tube with a shallower seat angle. The saddle can then be set central rather than set back, and a longer handlebar stem used, which might improve handling.

Toe overlap should not be an issue on a frame this size. You might consider longer chainstays so you are not sitting directly over the rear hub as this may cause shimmy problems, especially if you plan to use panniers. See my blog “Shimmy re-visited.”