The Buffalo is a slow float this time of year. We had a nice rain Sunday and Monday, but that will clear by the time you get there. Class I rapids (if your real technical about it). Nothing that should cause a turnover unless your just not paying attention. It will be a nice day. Deep pools probably average 10-12 feet. Deeper than that will be the exception.
I haven't fished the Buffalo in a while, but I live about 400 yds from a nice smallmouth stream, and olive or olive and black whooly buggers seem to be a goto. I like one with a little mylar rib on it sometimes to. You can agitate them into biting sometimes. stimulators EHC dave's hopper crayfish imitations. and go from there.
If you have any other questions, I hope I can help. Otherwise let me know how your trip goes.