Knowing your background, I say choose whatever gearing you want, but in order to make the 919 a bit easier to control with the wheelies (face it, yur gonna do it, right???) then that's where the suspension comes into play.
The forks are soft. WAY soft. Stiffer springs up front, and or an entire rebuild with internals are available. I think LDH (member on here, works at Dan Kyle racing) can rebuild the entire internals with Ohlins bits in the $600-$700 range. Everyone who has done it says it's worth it. Ohlins for the rear as well, Penske is a good option as well.
The 919 is fairly stable out front, but it wouldn't hurt to put a steering dampener on it to calm the tank slappers. Most say the 919 is stable out front, but it's not as stable as my Tuono (but it has a steering dampener). Again, assuming you're going to have that front wheel in the air, all this helps when coming back down.
Enjoy the bike! They are a ton of fun!
And PV, how the HELL do you get that many miles out of ANY tire??? You must be soft on the throttle, boy..... I destroyed my tires in 5k miles MAX.
My T is lucky to get one track day and 2k miles out of a tire,