I owned a 919 for about 20,000 miles or so, bitchin bike.
Love your build and I thought I'd contribute a bit of knowledge.
I had mine set up for commuting and the occasional canyon ride so I wanted better suspension than the stock, non adjustable units. I found a Racetech'ed CBR 600 F3 shock which was a bolt on and is 10mm longer than the stock one. It's also fully adjustable and comes with a remote reservoir that fits perfectly where the so called stock tool kit used to live. CBR600F4 forks slide right in as well and are compression, rebound and preload adustable.
I'm looking forward to see where this will go.