[SunRescue] Cheap SS4/5/10's?

[PaulKhoury-TechSupportpkhoury2 at stevie.loop.com]

I got a nice paycheck (since it's my last day tomorrow), and am thinking
of finally upgrading one of my SPARCs.
Any CONs of using a SS4?  I plan on using ONLY external HD's.  Also,
is memory standard, or proprietary?  I'd prefer an SS10, but I'd like to stay
below $150 if possible, for something with 64MB of RAM, and
NO hard drives (already got 5.2GB).

Also, do I just need to reinstall Solaris, and keep existing settings,
since I'd be going from Sun4c to Sun4m?

Thanks,

Paul