Can we use SQL express, or do we need to purchase the full SQL package?
You can use SQL express instead of a full version. SQL express is limited to 10GB max database size and 1 GB RAM (SQL Express 2008 R2).
Can we deploy Server 2012 R2
You can use SQL Server 2012 R2. Please note, you will not be able to downgrade to SQL Server 2008 R2.
What are the system requirements for os-soft?
The hardware specifications can vary depending on how the software is going to be used. The following document outlines the basic requirements and some hardware recommendations. (read more)