Configuration for a Sever

[Computer]

Hi,
what Hardware configuration do you minimum recommend to get a fast and stabil Vbulletin.

I have about 6000 Members, 300-400 Posts per Day and abaout 20.000 hits daily.

I´m thinking of a dedicated cobalt RAQ3 300 Mhz AMD with 256MB of RAM. Do you think this is enough memory ?

thanks