Take a look at the website for Australian High Performance Catamarans:



http://www.ahpc.com.au/



Look closely at how they attach the clew of the main to the main block--a strap fits loosely around the boom. The photos of the Auscat show the rigging well. Looks like all their boats use this system.



I'm sure you could modiify your currect H16 boom and outhaul to work with a system like this--and may not even need to drill any new holes!