Ultra60 with Expert 3DLite and PS/2 mouse - best OS?

I have an Ultra 60 set up with what is probably the best
configuration of hardware for using it as a desktop.

2GB RAM, Expert 3D Lite PCI video (VGA), dual 450 Mhz,
and 2 10K 36GB drives.

I have a Startech KVM which supports the mouse wheel on PS/2
fine in other operating systems than Solaris.  The PS/2
also works pretty good in Solaris on my Ultra 60, except
for the middle mouse button.

I had hoped to use Solaris as the desktop and get the
performance of the Expert 3D video, which isn't supported
in Linux, NetBSD.

But it seems XSUN doesn't support the PS/2 features
like the wheel mouse nor even the second button mouse
function of paste in X.

I've looked at open solaris and variations, but I don't
see any projects external to Sun, which work on sparc
and support Expert 3D video.  There is a developer
release of Solaris Express, but it has a disadvantage of not
being 100% compatible with blastwave add ons,
and no patches from Sun, etc.

It looks like I have to fall back on Elite 3D and open source OS
if I want my PS/s mouse to behave normally.

Does anyone have a suggested OS which behaves well with
PS/2 mouse, at least to paste, and also Expert 3D PCI video
for X support?

--Donald