What options exist to allow Solaris and NetBSD boxes to attempt to 
co-exist in a NIS+ environment?

http://www.theregister.co.uk/content/61/33338.html :

 Sun's Solaris x86 customers see the light of day
...
 More impressive is the Southwest Foundation for Biomedical Research's
 use of Solaris x86 on a cluster of 700 dual processor AMD Athlon
 systems. The researchers are also use Sparc-based servers on the
 back end to complement their high performance computing operations.
 Sun points to this customer as one example where a company can 
 save on training costs. The Solaris admins can go back and forth
 between the Sparc and AMD servers.
...

That's us. And of course, the article doesn't tell the whole story.
It doesn't mention that Solaris86 runs our executables at about
75% of the speed of NetBSD on the same hardware. Or that we have
all manner of strange network and memory behaviors (though Solaris86
is amazingly stable). Or that we are tired of Sun's essentially
null support of gnu/open source packages which make it exceedingly
tiring to hand-build the packages we need. Or the lack of support
for many modern x86 hardware devices, etc. Or that the only thing
the cluster uses NIS+ for is user accounts and automounts on the
cluster servers.

There are four reasons we use Solaris on the cluster:  We used it
on the older clusters for the last 10 years and on our compute
servers and desktops. The vendor pre-installed Solaris86 on the
cluster boxes. User accounts co-exist on desktops, servers and
cluster machines via NIS+. SGE (GridWare) is available for both
platforms and our code uses it.

I'm working on porting SGE to NetBSD (somewhat) though we wish
there was something better. I'm slowly trying to get pkgsrc to
where we can build what we need on Solaris. I'm experimenting with
replacing some of our servers with NetBSD when it applies (need to
get Python stack handling running correctly on -current...). I'm
looking for help in developing some more automated cluster install
and management tools for NetBSD (any experienced help looking for
a job?).

Essentially, I view NetBSD as the best non-Sun os for complimenting 
Solaris in our environment, but what can be done about integrating
NetBSD with NIS+? Ideas appreciated.

BTW, the next 400 cpus we buy for the cluster will likely be 4-cpu
Opteron boxes.  What's the word on 64-bit compiler support these
days? Some of our code is getting to the point where it will actually
need to address 64-bit space so we may not be able to run it with
these 32-bit compilers.

Thanks