Hardware Software Configuration for MS Dynamics NAV 5.0

We are looking to install Microsoft Dynamics 5.0 for about 30 or less concurrent users. From your experience, please advise:
Windows 2003 (Standard or enterprise) to run SQL and NAV
MS SQL: Version (2000 vs 2005 / standard or enterprise) Lic (CAL or Processor)
Server hardware: adequate for above.

We are a small company. I don’t see too much increase in number of user accounts. We might run eCommerce in the future to the database.

Your advise and point will be much appreciated.