Conti makes a 42c Top Contact II:
Continental Top Contact II 700c Tire at BikeTiresDirect
Unlike the Contact II, which is made in China, the Top Contact II is made in Germany and is stronger and more puncture resistant. I did a tour in MT a few years ago using Top Contact 37cs. The route included over 60 miles of unpaved roads. More than 20 miles of that was very rough in places. No problems. Going back there in June so I just ordered a set of 37cs Top Contacty IIs yesterday.
Personally, for road touring, 45c and even 42c seems like overkill. I did crossed PA in September via the GAP, the abandoned PA Turnpike and paved roads on 32c Contact IIs with no problems. But to each his own.