I don't know whether I'd buy another ball-head or go for a panning base and a monopod tilt head instead, even though you only have horizontal and vertical adjustment with no tilt adjustment unless you adjust your tripod legs.

eg a Feisol PB-90 panning base with a load capacity of 38kg for $US69.95, and a Kirk Monopod Head with a load capacity of 36kg for $US199.00, all up about $AU340.00. To get that carrying capacity in a ballhead puts you in the $550.00 + price range.