I'm also in LA, in Sherman Oaks. Out most weekend on ACH/AFH with my Z1000 or out in Malibu (Piuma/Stunt/Tuna) with my Husqvarna supermoto. If ya'll ever wanna ride, PM me.
Getting back to the stabilizer. The only non-Chinese eBay one that I know of is Dimotiv (DMV), which sells the bracketry only, and you must buy an Ohlins or Hyperpro damper unit for it separately. Total cost around $600, not cheap. You can always just get a cheapo eBay one for less than 1/10th the price, but don't count on it to save you from the tank slapper, it'll most likely just swap off during a high speed wiggle.
My biggest issue with steering dampers for the 3rd/4th gen Z1000 is the placement of it. They all mount up top at the bar clamp, instead of under the steering head like most other bikes. Great for those that wanna show off their new shiny new damper, but I think this is a really dangerous placement, to have a big chuck of sharp metal waiting to impale your chest if you land hard off a wheelie. I'm going to buy a used Ohlins damper and maybe make my own bracket that hide it down under the steering head.
But to be honest this bike doesn't really need it. With 25 degrees of rake, it's one of the most stable bikes I have ridden at speed.