C of A,
If any of the bikes you or your friend build look as good as your trike, they'll sell.
I agree with Silver Bear in that bike styles can often be catagorized by the target age group. Personally I like the old school cruiser look such as those built by Bairdco, Barley Awake and Silver Bear. I also am attracted to the cafe racer style and the boardtrackers. As they say, "beauty is in the eye of the beholder". Good luck with your venture.
Age and Treachery Will Always Triumph
Over Youth and Skill & "Charlie Don't Ride"