Nothing wrong with a 1" head tube. There are 1" sus forks out there, though admittedly they'll be hard to come by. On the other hand, a suspension seatpost can soak up a lot of the pain or you can track down an old 1" rigid with tons of rake and it will be a pretty cushy ride.

I suspect it'll be hard to find a frame with a 1 1/8" head tube and horizontal dropouts as the one was pretty much introduced as the other was leaving the scene. If you want that you'll probably end up having to either put new forkends on a vert. dropout frame or buying a new SS-specific frame.