Re: Rod Length
Fishing every stream with the same rod is like trying trying to play every hole on a golf course with the same club.
A nine footer will be too long for some applications and a seven footer will be too short for others. Being rod length has little, if anything to do with casting distance and everything to do with mending and line control I would select a rod that is best for the waters you fish regularly and not the ones you might fish. An 8 1/2' would probably fit your streams and give you something still usable on smaller water.
If you can go for two rods, go with a 7 1/2' and an 8 1/2' or 9'.
"If people don't occasionally walk away from you shaking their heads, you're doing something wrong." John Gierach