Reporting Services is part of the SQL Server 2000 license. There is not a separate license for Reporting Services. If you have a licensed copy of SQL Server 2000, you may run Reporting Services on the same server for no additional license fee. If you want to run Reporting Services on a server that is not licensed for SQL Server 2000, you will need to obtain a SQL Server 2000 license for that additional server.
Yes, a copy of Visual Studio .NET 2003 is required for each user who will use Report Designer, the report-authoring tool that comes with Reporting Services. Visual Studio .NET 2003 is not required for users who only view reports.