MNNTHBX upper triple clamp for 1 1/8" bars is pricey but absolutely the nicest solution for adding larger diameter bars and with it's four positions allows far more flexibility than other options.
Pro-Taper 7/8" KLX110 bend bars are a nice add-on and reasonably priced.
Driven Racing 1 1/8" carbon fiber SBK bend bars...super nice, look absolutely bad *** but, because of their being far lower, won't allow a full lock-to-lock turn without touching the tank cover and that is with them on the farthest forward position on the MNNTHBX upper triple clamp. Not a huge deal but something to keep in mind.
ASV C5 levers...very nice, well made and just about infinitely adjustable but at almost $300 a pair now I can't recommend them. If I hadn't already put a set on my daughter's bike I wouldn't have bought a similar set for my bike. I tried to get Pazzo Racing levers, which is what I have on most of my other bikes, but they don't make them to fit the Z. Makes the eBay 'Made in China' levers look far more attractive although I can't vouch as to how well any of those levers might work or the quality.