Mults: too many, i like the Bidoo (Sigma) Multiprise for this kind of application
Anti-mults: mL Modules Sum8 (either one)
A/B Switches: umm… good luck there’s so many.
Attenuaters: Too many, but my personal fave is the AS Atnvtr (CV-able Befaco Dual Attenuverter)
Rectifiers: 2 choices. Audible Utilities (top section) or the BBI GetRekt.