For work and from my experience, Saluki crosses. My uncle got talked into buying one years ago when we were out working our collie crosses on a very regular basis. The dog would catch ok, albeit being a bit cumbersome over rough ground and short distances, would then proceed to bite the rabbit in half and then do about 20 laps of honour with the minced rabbit, scaring everything else off in the distance, especially if we were lamping. It came back "when its ready" and was, to be fair, thick as a stump. It was a lovely animal but we just could'nt get it to work half as good as the collie crosse