All of your upgrades sound good (not really necessary though) but I just have a couple questions / suggestions. Why the SRAM cassette. Don't get me wrong, I really like SRAM and in most applications I prefer it over shimano. The only exception is the cassette. I would rather have an XT cassette over the pg-990 any day.

I think you will be just as happy with the SRAM front derailleur as you will be with the XTR. As far as the rear derailleur unless you are trying to save weight just go for the X.9. I have the X.9 on one of my bikes and the X.0 on my other one. I can't tell any difference.

I wouldn't bother getting the hollowpin chain either, not really necessary unless you want to save some weight. Once the 951 wears out just get a 971. It's a great chain and costs a good bit less.