+1 on an older touring frame. Used ones are available in large numbers for great prices, and they're made to feel relaxed for long-distance riding. Go to garage sales & flea markets and look for rack mounts on the fork or rear stays.
Don't know off-hand about what's currently being made, though.

Edit: look in the path-racer thread on FGG to see what some of those guys used. Most of those bikes will be right up your alley, as long as you set yours up with the components you want.