How to size a Forum
 

We are planning to migrate our Forums to vBulleting.
Does any one can provide guidelines for Hardware and Software platform based on the size of the forum we plan to run.?

As of today our numbers are:
PER MONTH:
Forum Page Views: ~4,500,000
Msg Posted: ~3000
New Registrations: ~600

Total number of Registered users: ~ 100,000
Total Number of messages: ~130,000

Can you recommend on the desired platform (# of CPU, RAM, HD, Database, Bandwidth etc..)

Thanks