I believe the lower resonance G12H was the one used in the original Orange cabs and the Marshall bass cab. The speaker was designed for bass which is why it has the lower resonant frequency. It was used by a lot of guitarists though because it gave a cleaner bottom end over the 75hz.
If I was putting a G12H in a cab it is the one I would go for, but then I put the heritage G12M in my miniMat cab! I think with the V30 it will be a good match, unless you want more bass 'growl', in which case the 75hz will do that.