Gernot,
I think that's a great idea. Especially since
http://www.capedwonder.com has such great action shots of Mr. Reeve in action.
Another possibility is that I know that DC did comic adaptions of SUPERMAN III and SUPERMAN IV. I don't know if they did adaptions of I and II, but if they did, collecting these under one cover, or even re-issuing them separately with the CHRISTOPHER REEVE shots that you proposed could be good.
JMR