Look for Clark Tanks.. I think they may still make them. I have a 3+ gallon on my 83 and it's slim, my brother has 4+ Clark on his XR650 and the quality is impeccable.
If you can stand a used one, eBay is always a good place to look. I have had some minor luck at improving the condition of used plastic with 3M plastic polish.
I had called Clark and they said all they had was for an 89 KDX. And I was wanting to avoid buying a new one from Kawasaki. And I have been looking for a used on for quite a while with no luck so far! Thanks for the replies I appreciate the help. John