In my opinion, this is the best way to go, either street or track.

I've seen a lot of people suggest an OEM CBR 900RR shock for the Hawk, and have seen them in person. That's a pretty cheese-ball mod to the bike and really not worth the effort.

If you are going to try to upgrade your suspension get a Penske or a Fox that is made for the Hawk and you'll be much better off.