Didn't Martin King do a lot of work on those? I'll bet he has an excellent design for them. Rarely do I see as much effort put into system design for single drivers as he does, so I think there's merit in his ideas. Plus, they sound good too. A guy could have Bill Martinelli build King cabinets and have an extremely attractive and high-quality system. Another good option would be to go with Cain & Cain speakers. Terry Cain is another top-notch woodcraftsman, although I'm not sure if he supports Lowthers or not. I suspect he does though; Perhaps he'll chime in and clarify.
Both Cain and King are pretty well-known in these circles, and I think they both have well-deserved good reputations. Can't go wrong with either one in my opinion.