Hi tv175,
Thats a very neat conversion
You dont tell us where in the world you are located, which may help with the choice / availability of suitable carbs
Flange mounting adaptors can be fitted to your head if space allows, these would attach to the head with simple rubber connectors as mentioned
My personal choice would be to fit stub fitting Mikuni VM carbs,
Other than that how about trading me your twin carb head for a single carb one ????
Regards
John O R