I have the carlini 16" on my deluxe. They are closer to 18" then 16" if measured. I went with +10" on everything. I wish I would of done a +8" on the front brake just cause I have a bit too much slack. I should be able to go with 18" bars if I wanted and cables should fit fine.
So in short Id say +10 for throttle(s) and clutch and +8 for brake.
I think its been posted in here before, www.handlebarcables.com they have kits and pt#'s for just about every bar in the Drag catalog
I was just looking for an LA Chopper bar(one of their new ones) and did not find it on the list on that site. We are going to be partnering with Chucky at LA Choppers to provide all the cables for them. Hopefully I'll be able to get you guys some nice deals through him.