ETL Server Hardware configuration

I would appreciate it if you guys can provide the specifications of ETL and Database Server along with the Datawarehouse DB size and number of users you guys have.
Example Server Type(Intel/Itaninum etc ) , Number of CPU/cores / Memory / Disk configuration and size .
We are planning to upgrade our env. and to start a new project, I would like

If you are on Oracle have a look at the Oracle Optimised Warehouse Initiative for reference configs:

http://www.oracle.com/solutions/business_intelligence/optimized-warehouse-initiative.html

For formulas to calculate hardware specs have a look at (again for Oracle):

http://www.amazon.com/gp/product/0130325848?ie=UTF8&tag=busineintellq-20&linkCode=as2&camp=1789&creative=390957&creativeASIN=0130325848

It's a bit older but still has relevance