Regarding Mavic/Simplex retrofriction levers with modern index gearing, I have had excellent results and no problems with 9 speed clusters. I haven't tried 10, but I've heard from more than one source that it works fine. In my experience with 9s there is still a bit of lever travel left over.
I'm also using Suntour barcons with a 9 speed cluster with no problems.
Bob Schenker
Oakland, CA