Keep in mind the contrast in the attached examples has a lot to do with the lighting in the original scene. Depending on the lighting, conditions and colours of the subject matter, you may also be able to increase contrast with filters on the lens.
Also just a reminder a 400 speed film with Rodinal will be pretty grainy, depending on the size of the prints you make. You're shooting medium format so you have some more flexibility there. But in general you can get just as much contrast with D76 as Rodinal (since you mentioned D76). D76 at stock strength and continous agitation in your Jobo will do fine, and the results will be significantly less grainy than Rodinal, albeit with slightly less sharpness. The difference in graininess will be bigger than the difference in sharpness.