assuming you're doing some work in your own content creation software, I would do it there and not a displacement map.
In nurbs, you just do an offset surface, then trim your shape. In something like polygons, you just project your shape on with something like a shrinkwrap modifier in blender, then use thicken for your offset.
Controlling displacement on custom graphics is a pain in the rear. It's definitely worth just modeling it if it's a simple shape like that.
To get a custom graphic like that smooth, you have to make it a crazy big resolution image, convert to 16bit. Then blur slightly. Then in keyshot use an insanely high number of polygons to get no artifacts at the corners. Oh, you found the edge got a radius too much from the blur? Now go back to photoshop, change the blur number. Save. Go back to keyshot, realize that you used GPU so you can't actually refresh your graphic. I know I know, that'll be fixed in Keyshot 10 right? So restart keyshot or go back to photoshop and save a copy. Replace them image or finish restarting keyshot. Then recalculate and wait. Shoot. You tightened it up, and now got artifacts again.
Anyway, you get the idea. Displacement works well for organic shapes, but doesn't work well for sharp corners....at least not in keyshot.
