Interesting that he didn't like the DSS pipes. Were they the replicas of the originals that they sell?
I would very much like to see some detailed photos of those pipes and what specifically he didn't like about them. Only because at $400 odd dollars, I'm contemplating buying a set rather than having my originals rechromed for likely many times that price.
All the manufactures that I've heard of have been listed below, but in my opinion none of them look as good as the original pipes, they're what make the bike in my eyes.
However, and I'm not exactly sure they'll fit on a stock CB400F, but perhaps a set of CB350F pipes might be to his liking? I've always liked the 4-into-2 pipes on those bikes.
Good luck,
Rick.