I'd have to mention the Venture 60 just because it's been mentioned to me. It's designed by the guy who originally did the 4*40 and 4*120 and is his idea of how a 4*60 should ideally be.

Take a look: http://www.btemodels.com/venture.html

EDIT: Huh, just noticed Connery just mentioned this plane as well. See... it is popular!