Thanks guys for the info so far,
Some interesting reading,

I was initially aiming to get the COG to the front of the range but am feeling now that by leaving the weights off and setting th SG to the rear part of range it still may be better to fly for a beginner than the heavier alternative,
Being that any gain of stability by having frontward CG will be offset by the extra weight added to accomplish it?

I am going to have the plain flown by an experienced pilot first so might ask if he can fly it with and without the weights to make a judgement for me what is better,
I guess that if the plane is within its COG range it should still fly ok,
By moving the COG back by the half inch it requires no extra weight,

Cheers,Paul