I think you are on the right track - i.e. going up 2 rod-classes between setups. My standard arsenal consists of 7wt, 9wt and 12wt. 11wt was a bit of an odd-ball size when I put my original kit together.
I also have a 13wt which can be comfortably cast and a 14wt which is limited to single shot water-haul techniques.
Thats in addition to a few double handers and light weight stuff for freshwater.
When sight fishing, look over your shoulder from time to time, you never know who's behind you