[rescue] ss10 upgrades ?

[mike tuffs]

I just found a nice SS10 for $20 at the Goodwill, it has:

40 Mhz CPU
128 mb RAM (5 cards)
9 gb SCSI
GX graphics
clean install of sol 2.6 with a root account with no password (yeah)

So:
Should I stick with Sol 2.6 or is there something better ? ( I might 
try & run some work stuff, which will want a later version of 
Solaris...)
Looking on the web there are faster/multi processor options available - 
does anyone have any old mbus
cpus ?

Any help appreciated,
Mike