[shrek]

I've been meaning to take a look at Data General Unix (DG-UX). According to Wikipedia it ran on m88k and x86 (32-bit), so if I can find the x86 installation media it may not be difficult to virtualize it. It uses the Motif based X.desktop as the GUI, which I have never tried before.

And while it's not technically SysV based, there are also the early Mac OS X previews like DP2 which uses pieces of the old MacOS 9 interface on top of Darwin/XNU and all the other stuff that's under the hood of OS X. For actual Unix from Apple there's A/UX which is somewhat known but still obscure.