From the drawing I found at
http://notasperdidasenlaweb.blogspot...1-shinden.html it looks like the final CG location will be pretty near or only slightly back from the leading edge of the rear plane wing root airfoil. This being based on the idea that the main gear would be located on a line swept back from the vertical through the CG at around a 15 degree angle
Your selection of a 24016 or 24011 would likely be controlled by the size of the model. All else being equal the thinner airfoil would do better on a smaller size model such as a smaller to medium size electric or glow powered model. Once you get up to a 5 foot span or larger the Reynolds numbers become high enough that the thicker 16% section would do well.
Alasdair, the 240xx series are a lower or neutral pitching moment style and should be fine for this sort of use. But I agree that making the fore plane with a postive camber airfoil would be a wise option. Tim something like a NACA 2410 would not be a bad option for the foreplane. Or on a smaller model just use 1/8 to 1/4 sheet surface depending on the model size and sand in a reasonable approximation of a Clark Y.