Woody,
If you already have a 380 then I would assume it is a 5.5 turn winch. For the EC12 some may get by with 16" of travel but most use 16.5 with the jib trim function. Hence, I think you will need Bob Guyatt's 32mm drum. You may ask him, by email, if he can make a 32mm SDS, spiral step down, drum. That will give you a bit of close haul resolution than without it.
The other option is to get the conversion for the gearbox from Bob, it is cheap, that will convert the 5.5 380 to 11 turns. Then you could use a 20mm SDS drum that would have better resolution.
Hope this helps you make a decision...Rick