Guys have found a 95/96 CBR900RR shock and adapted those with some success. More of those kicking around than parts for a Hawk...
I have a Fox twin clicker CBR900 you could adapt. But a shock from DMr or Hord would be good options too.
Bite the bullet and have JD Hord get you completely set up, front and rear. The dude was one of the fastest Hawk racers, in his day, and definitely knows how to set one up.
I called him about some twin shock penskes I bought from an Ahrma guy who had him build them. He wasn't very helpful, he told me to call Penske since he doesn't build them anymore. I figured he would potentially know more about them considering he built them, and I had all the paperwork where he did. I've heard good things about him, and tried to use him, but he seemed to not be interested.