shoota, I wouldn't worry about most of Siimano's 9S parts. You will pay a premimum if you want a part to come from a box labeled Ultegra or Dura Ace. I bought two HG-50 14-25 9S cassettes that look exactly like the old HG-70/90 non Ti cassettes with the Ultegra style spider and drilled cogs.

I'm less sure about Octalink V1 bottom bracket availability in the future. I guess if I were really worried I'd order a BB for my 6503 bike.

Brad

PS I had one 7700 bike and two 6500 bikes at the same time and the most noticeable difference, other than in my wallet, was the superior FD trimming with the D-A.