Redistributing SQL Server Express

Can anyone direct me to where I can download a redistributable (setup) for SQL Server Express w/Sp2 that is for both 32 and 64 but systems The only on I can find on the MS website is 'en_sql_server_2005_express_edition_sp2_x32.exe' and appears to be for 32 bit systems only. Will this install on a 64 bit system

Also, if anyone has any tips on integrating this into an InstallShield InstallScript project, they would be welcome. I am assuming I can just launch from within my install since it is not MSI based, but have not tried yet.

I will need to either install a new instance or upgrade an existing instance depending on the presence of that instance. Any easy ideas welcome.

As far as I am aware, SQL Server Express in only available in a 32bit version -that will run on a 64bit OS using WOW.

You can verify that here.

http://forums.microsoft.com/MSDN/ShowPost.aspx PostID=1688823&SiteID=1

And check the redistribution requirements here:

SQL Server 2005 Express Redistribution
http://www.microsoft.com/sql/editions/express/redistregister.mspx

For automated installs, you may find these sources useful:

SQL Server 2005 UnAttended Installations
http://msdn2.microsoft.com/en-us/library/ms144259.aspx
http://www.devx.com/dbzone/Article/31648