Todd, I wish I knew more about stab design... the only thing I know is Mike Harrison once was coaching me and pointed out that stab size had a tremendous effect on spin entry and slow speed stability...I never did get to follow up with him much.

It seems that more successful 'current' designs have a lower aspect ratio; not really a lot of span, but plenty of squares near the root. The three birds in my house right now appear to have same percentage thickness as the wings, and the same planform....and I have no idea why, unless it's to "make it look about right"