I planning to use my XT 770 crank arms with a 24/36 chainring set up in 9 speed. I assumed that I would use Shimano XT or LX chainrings however I can't find a nine speed XT or LX in a 24; plenty of 22's and 26's. There is however an XT 24 in a ten speed as offered with the 2011 cranksets. This being the case I can go to FSA, Truvative or Blackspire who all make 24 and 36's for 9 speeds. Any recommendations for the best shifting units? I'll be using an 11-34 nine speed cassette, an SLX FD and XT RD.