smoothwall/mac/windows

Hello
recently bought a very old mac PC at a Car boot sale (yard sale)
has got a CD drive and would appear to be severzl years old I am no expert on the Mac OS so would not know one model from another

and was wondering if i could wipe the HDD and use it to run smoothwall in between a windows based pc and the WWW could some body pls give me any advice or links to a site the explains the process
thank you

Processor: All Pentium compatible processors, including Pentium I, II, III, IV, AMD 586 onwards, Cyrix,
and IBM. A 150 MHz or faster processor is recommended.

So... nope.

thank you for your help
bty.....................any idea whay a power pc performa with the numbers 6320 on the outside or the case is woth in $ or £

$6,134,549.99