Thanks again quick61 and G Don, and a bit of a sorry on my part as I was planning shear webs but did not know that they were known as a 'C spar' once fitted to an upper and lower mainspar arrangement.
Calculations are all being made off my first 100% selfbuilt model - the 'Kombat Kid' by ProBroJoe. Build thread on that one is here:
And the micro version of it is here:
So the natural progression after making a smaller version is of course to make a larger one! Both large and small wings fly very well and I can only imagine the current build will fly better as its using a dedicated flying wing airfoil and will have an equal or lower wing loading when finished.
Cheers - boingk