Here is a complete RC51 SP2 brake upgrade. It should be directly swappable with your 919 or CBR600F4i or RC51 forks. I had RC51 forks with 919 brakes & swapped these over with no issues. I cannot guarantee the calipers will fit the 919 as-is or might require a tiny bit of shimming which can be done easily with some stainless washers. A search on the forums will reveal folks who have gone that route.
Of all the mods I have done/experienced on the 9er, this is THE BEST IMO you can do. Not only is it functional but it will greatly enhance your riding experience simply because you feel so confident on the brakes. After installing these, I spent quite some time just riding & stopping because I really enjoyed it
If I could transfer these over to my GSXR I would no question, but I cannot.
Moving on, here is the break up of the parts & how much I paid. The pads are as good as new, probably 2K miles of use. As you can see in the pics, the calipers were thoroughly cleaned. A very good condition set. Existing 919 brake lines will fit right in. Please remember to install with new crush washers.
RC51 SP2 brake master & calipers - $150
Brand new RC51 SP2 OEM brake pads - $60
CBR600F4 OEM mirror less clutch perch (this will accept your stock 9er clutch lever) - $15
Chinese Mirror adapters from Amazon - $6
Stainless bolts from Lowes - Forgot cost
Total I paid $230
Yours for $190 shipped Priority Mail. Or FedEx ground if you are very close to me.