I would be very interested in see how you would accomplish this. I did this project on a Santa Cruz Tallboy earlier this year. However I used the Ki2 kit from K-Edge
The kit is hassle free complete bolt on with no modifications necessary. Comes with a modded rear derailleur and custom made shifters. The outcome was very good, smooth, precise shifting.
How will you mod the shifters? Will you machine your own?
Yes, the RD cable looks short, but no choice but luckily it worked. There is no other way to wire this on a Large 29er frame, I am glad it was ok, otherwise so much trouble to mod it or send it back.
True it is more expensive, but just easier. How will you mount the Sprinter Shifters?