I've got a small SPARC system which is /just/ /about/ running Debian, but I have no media- at least that I trust- for Solaris/SunOS and am extremely reluctant to start trying to download stuff.
SPARC hardware is, by now, unobtanium: anything low-end vanished into skips and museums ten years ago, and anything high-end is being sat on by spares vendors in a vain attempt to keep the few remaining corporate users afloat at a price marginally less extortionate than Oracle's.
I think I had Solaris 8 at one point, but no longer. I tried a DLed 10 which was supposedly free for non-corporate use, but it self-destructed suspiciously close to one year after I started using it. I've used- and been generally impressed by- OpenSXCE, but that project was run by a self-identified Russian in Eastern Ukraine and it self-destructed with considerable acrimony on 2014.
That is about as much light as I can throw on the situation at the moment. I know that there's at least one person in the community intermittently hacking on a very old SPARC "lunchbox" system but I suspect that his version of Solaris would be far to old to be relevant.
MarkMLl