John, also please note that the rim in your photo is drilled for a smallish hub. You'll need to decide what diameter of hub you're going to use on the rear unless you're going to fit the existing H-D hub and rotor.

For a particular cafe project, I managed to find a wide aftermarket DID 18" rear and matching front laced to a Kawasaki drum rear and disk front but it took me forever and cost way more than I wanted to spend! So, although they're rare, they're out there but it takes time to find them. RR

If you're not living on the edge, you're taking up too much room!