Here's the best lane splitting set-up going bar none (get it?).
Cut-down Henry/Reed Protapers
Real Acerbis RallyPro handguards
ACNMW bar clamps (no longer available, but equivalents are)
Stalk mirror (from a KTM 990 SuperDuke)
To determine how much to cut off the bars, mount the right-side controls and slide them in as far as possible, then mark and cut off the end. I used a different master cylinder, but I would expect you could get 1/2" or so with the stock master cylinder.
If you are truly lane splitting, ditch the stock "handguards". At over $300 per side, you will be sorry if you don't. If someone crowds me and I clip their mirror, I win with the Acerbis handguards. You'll have to massage the Acerbis to get a fit, but it can be done.
Besides, the flip out bar-end mirrors make the bike too wide and, if you aren't using your mirrors while lane splitting, you're asking for trouble.
The stalk mirror isn't as pretty as say the CRGs bar-end, but it is infinitely more useful in close quarter trafffic.
Now, excuse me while I go merrily down the lane splitting...life is but a dream.