You really won't go wrong with the lavry gold, although the MkIII, we're told, runs a little cooler than the MkII.
You want to improve on it? Tried running it as master clock via word clock?
Others of this "league" are the Prism and Weiss models, but another lesser known one I used to use, and known for it's A-D more than its D-A, is the ADDA 2408 from
Digital Audio Denmark.