Bruce:

I have been designing regular size airplanes for the past 45 years, and big ones for the past 27 years. All of them that perform really good have had the incidence angle set at 1 1/2 to 2 degrees positive, when the stab is at zero. I think this is the right range for you also, with the airfoil that goes on the type of plane you are contemplating. At one time I did a study by changing the incidence angle from zero to about plus five degrees, and the differences were unbelievable. At zero degrees the airplane was hard to keep level - it either wanted to climb or dive - no in between. At angles above two degrees, it didn't fly level in the air - it mushed along if you know what I mean . Of course, this study was done on a flat bottom airfoil. Fully symetrical airfoils can be flown at zero degrees with good results.