Looking great. I vote for the balance lug. It's a great little rig. I am building the John Welsford 6M Whaler. It is a lug yawl. (Well, it's got a sprit rigged mizzen, and a balance lug main.) What you'll love about this boat is that it is built much like a SOF. You have ribs and stringers. The lapstrakes glue to the stringers. Very lightweight yet very structural. It's like a SOF skinned with thin plywood. So far I have the station mold half-form patterns made from 1/8" ply and am now awaiting the arrival of the marine oakoume and mahogany ply for the actual forms. Meanwhile I'm ripping up some old masts I salvaged from a wreck and making hollow birdsmouth spars. The whole boat rigged is only 600 pounds. For a 6M boat that's pretty light. I am adding a small cabin and raising the coaming, so I will have a bit more weight, plus a bit more ballast to offset that weight.

http://www.jwboatdesigns.co.nz/plans/6m_whaler/

The hard part is I have to make a centerboard out of 1/2" steel and then ship it off to be galvanized. The good news, however, is there is no lead ballast, so I don't have to fiddle with melting heavy metals.