I'm wondering if this is one of those times when you just need HDR to replicate what you see. I'd try exposing for the sun, which should create a nice disk, but dramatically underexpose the foreground. Then blend that image with one properly exposed for the foreground (possibly with some intermediate exposures as well if those two extremes differ by too many stops).
Note that the sun is massively overexposed in all the shots where the sun shows up as a star shaped flare, while the sky surrounding is more normally exposed. If you're looking for that sort of effect I think you need to have a clear sky to contrast with the sun rather than clouds which will scatter and obscure the flare (that and a lens with flat rather than rounded aperture blades). Most folks prefer rounded blades for the cleaner bokeh they produce, but if you want sharply defined diffraction highlights in your flare flat blades are the way to go.