Parts availability is a good question. I run a small fleet of older bikes, so I'll give you my break down on it.
It helps to own more than one bike, which you do, in case this one is down during prime riding season. Even for new bikes where parts are regularly available, it can take 2 weeks to get them! So the handicap of an older bike's parts availability is not much greater.
You don't have to know a local Kawasaki dealer, plenty of them sell parts online. I know Honda does a good job, I'm sure Kawasaki does as well, it's not Aprilia we are talking about there... and the aftermarket seems to take care of the rest, including NOS and used parts on eBay from the breakers.
Big bikes, even older ones, have high value to their owners. Current owners will spend money to keep their bikes on the road, so breakers on eBay will find the wrecks and part them out. Sometimes you may have to wait, or bargain with overpriced eBay sellers.
It helps to know shared components with other bikes, the parts sellers may not know every application, and be limiting their market artificially. If it's been listed on eBay for months, make an offer, you'll get a sale, or at least a counter-offer.
Know all the documented and undocumented maintenance routines, to avoid trashing the expensive bits.
In the past couple of years since returning to motorcycling, I've gotten into every aspect of maintenance and repair except for engine lower ends and transmission rebuilds (no need fortunately, nor desire, lol). I bought an air lift, which would be a real luxury for automobiles, but an affordable luxury for a multiple bike owner. Non-air lifts if you are very frugal, still worth every penny versus kneeling and bending. Again, having multiple bikes give me the courage to tear into a seemingly difficult job with confidence, knowing I can hop on another bike when the inevitable stop-and-wait-for-a-part happens.