Old Testament Message / New Testament Message, an accessible commentary from Michael Glazier imprint, would be an excellent addition - especially Carroll Stuhmueller on the Psalms. It's a nice intermediate step for those who have outgrown the one volume Collegeville Commentary.
Michael Glazier's The Passion Series (one for each Gospel) should have a great deal of appeal as well.
While the Chrysostom Bible Commentary is just started this commentary from Tarazi out of Orthodox Center for the Advancement of Biblical Studies should appeal to a broad audience ... this is a series "to die for"
Yes, I know these would take a while to get out of pre-publication but once people become familiar with them, they should provide nice steady sales.
