Thank you all for all the replies and suggestions.

I am not a hardware person and on SQL Server forums generally hardware is not discussed from what i could find.

As for some of the questions raised by Old Hand which are very valid,

The 1 TB size will include about 3 years worth of data and for a data mart and not the warehouse. That is going to be planned couple of years down the road.

There will be a max of 20 concurrent users and also worth mentioning that the data load needs to happen every 15 - 30 min intervals throughout the day.

Business Objects is going to be the front end toolset (WEBI and Crystal) and the ETL Tool (Data Integrator).

This is going to be used mostly for canned reports to begin with and analysis coming later. The user expectations in regard to the query performance are not that high at this point.

Backups and DR scenario is something i have never dealt with on this scale and size and would appreciate some input.

Although the hardware ( the architecture, the choices and the vendors) change very often, there ought to be some general guidelines to start sizing the server just like you have for a database configuration especially if you are starting off with a new requirement.

Thanks again for your input.