Yes, you can host almost any of ASP.NET applications that build on SQL 2005,SQL 2000 on MSSQL Express Database.
Most of the features such as Stored Procedures, Tables, Views are compatible with MSSQL 2000 ,and MSSQL 2005.
In all our webhosting plans, we do offer FREE MSSQL Express database.
However if you need better performance for your website, we do recommend you to purchase MSSQL Database as it is more reliable and hosted on better spec dedicated server.
