> 
> Thanks! I hope I can show to the bosses... :)

better show them 4-CPU server with 10 disks, 4GB of memory and windoze. 
they will be more happy. bosses don't like good solution - they prefer
well advertised ones
 
> Have you any info about 3000 user?
WHAT USERS?!

if ones that sometimes need to view www-pages same configuration should be
enough..

get pentium III, 256MB RAM, multiport nics (to separate subnets) and 
IDE disk drives for mails and maybe www cache