N00b Question on minimum HW req's

Hello all,
I need to get hold of a box to install a base OS and Oracle 9i
Database. The system can be a performance shitter, only requirement
is it has to run and provide base functionality for us to get up to
speed on a few things. I've been looking at Ebay and there seem to be
K and D class machines that look like they meet these numbers for
under $300. I've also seen C100 and C160 workstations that look like
they might work as well. Any suggestions appreciated.
Thanks.
Stan