There's nothing to stop you from doing what you want, but I'd urge you to research job opportunities for Solaris device driver writers before committing to your strategy irrevocably. My hopes would also be that you are located in the Bay area in California or in some other place where Sun maintains developer centers, simply because such operations usually create the best (and most) opportunities for this kind of work.
Alternatively, you'll want to cultivate relationships with key providers of storage, networking and other devices built for Sun/Solaris servers and workstations to ensure a steady flow of work. Without due diligence to make sure this is feasible, I can't recommend that you follow this strategy purely out of your hopes and desires to make it work. Those characteristics will help you enjoy your work to the max, but alas, they won't pay the bills!
Good luck in pursuing your inquiries. I hope you learn that you can indeed follow your inclinations and do exactly what you propose.
This was first published in March 2003