Do the Hydrovac yourself! So long as you take some pictures of the tear down, they arent hard to rebuild.
ABS Power Brake has NOS units for about $150. You can get basic kits (all internal seals needed) WITHOUT the control body diaphragm, lead faced valve and the power cylinder seal for about $50. You may not need those three components.
BSC is a pain in the butt to get kits from as they would rather you send in yours for a rebuild or replacement, but if you argue you can get kits. They DO NOT like responding via email so your better off calling.
Jeff