Sql-server – Microsoft SQL Server Data Limit

Is it likely your transaction log file...the backup will want to create one as large as was on the original.

Your best bet if this is the case is to shrink the log file before you do the backup.

Another option outside of backup if you can get away with it is to detach, and then copy the database file and re-attach, SQL will then create a new transaction log file at the default size of like 1mb.

To quote MSDN:

In SQL Server 2008, you can restore a database backup that was created by using SQL Server 2000, SQL Server 2005, or SQL Server 2008. However, backups of master, model and msdb that were created by using SQL Server 2000 or SQL Server 2005 cannot be restored by SQL Server 2008. Also, SQL Server 2008 backups cannot be restored by any earlier version of SQL Server.

So, yes, you can backup a SQL2000 database and restore it to SQL2008, the only caveat being the master, model and msdb cannot be transferred this way, so you will not be able to migrate those. Thats probably not going to be an issue though - on shared hosting you are unlikely to have access to master, model, and msdb anyway.

However, if you need to migrate back to your SQL2000 DB from SQL2008 you will find that more difficult as the 2008 backup file will not restore on 2000. You are probably best to ensure you only need a "one way" migration path, and completely avoid the need to rollback the migration.

Regarding comparing Web and Express, refer here. Expanding the "Scalability & Performance" node shows that with Web Edition you get up to 4 CPU's, as much RAM as you like, and DB size up to 524PB (thats PetaBytes!) So Web Edition should last you for a while once you outgrow Express.