For years I've watched a few of the surviving episodes of these two dramas from the sixties, and hace wondered why they've never been released officially.
Empire is a 'modern western', with Richard Egan as the administrator of a big ranch owned by the rich Garrett family, and among the regulars in this 32 episode one hour drama from 1963 are future superstars Ryan O'Neal and Charles Bronson.
If The Wide Country and Stoney Burke have been released, there's no logical reason for Empire's non appearance, specially since it was filmed in color.
Long Hot Summer, based on the fifties Paul Newman movie (but also inspired by current hit Peyton Place), is a one season serial (30 one hour episodes) from 1965 also filmed in color, starring future The Invaders star, Roy Thinnes.
There's 13 episodes available in the collector's market (and in YouTube),
I would say there should be a lot of interest, specially due to Thinnes status as a cult star.