The Pearson 35 and Tartan 34 keel/centerboarders were both made with yawl rigs, but they are pretty scarce. I recently saw a Tartan 34 on Yacht World that had the yawl rigging available with it, but was not installed. Pearson 35 yawls are (slightly) more common. Also: Allied Seabreeze 35, a very pretty boat but somewhat underballasted, espec. as a centerboarder, and Bristol 35, same centerboard/ballast situation in my opinion. The deep keel Bristol 35 is probably a better choice. There is a sweet little Bristol 32 yawl in my area. I believe they are relatively common.
Other alternatives to the Hinckley B40 would be the Block Island 40 and the Bristol 39/40, both very similar to the Hinckley but generally cheaper, espec the Bristol.
I, too, find yawls attractive, but scarce. I ended up with a sloop, impatience having overcome esthetics. Best of luck; "perserverance furthers." (I Ching)