Sun did make a couple external drive boxes, such as the Storedge D1000
which takes SCA80 drives, I have one personally although I've never used it
as I don't own enough drives to make use if it at the moment, running 2
drives in an 8 drive enclosure is kind of pointless.
As far as UNIX systems go, the only one I really own is a Sunfire V480
(Quad 1.2 GHz Ultrasparc IIIcu, 16 gigs ram, dual 37 gig hard drives), too
new to be called "classic", although as far as modern systems go it's
completely worthless as no one supports SPARC III processors, except the
Linux community and Solaris 10. It currently sits unplugged doing nothing
as it uses so much power and produces so much heat that running it 24/7
would be a pain. It does see occasional use testing Linux programs, I can
confirm that Unreal runs with compiled from source, and Debian 6 is the
only Linux that will install.