I just refused to buy into a commercial balancing system - most of them don't look that sturdy anyway. So, I bought a bunch of 'end-cuts' of 2" brass bar-stock - readily available from any good scrap metal dealer. Some aluminium 2" x 1/8" flat bar (again, scrap ends) and some 1/2" 'Unistrut' (again, scrap). A few lengths of M10 and M8 rod and bolts (Stainless steel - cheap at good hardware outlets) and some M8/M10 nuts, bolts and washers - and an M8 tap. Job done.
Took about a year to plan, and about two hours to implement - having TOTALLY abandoned the 'plan' altogether, because I couldn't be bothered firing up the Milling machine ! (see the "3D Balance System - Engineer's Plan" image)