64-bit versions of Revit 2009 products are not currently available.
Revit 2009 products can be installed on a 64-bit operating system in order to take advantage the memory allocation feature.
If you create a Revit Deployment image, you might be confused by the check box of either 64 bit or 32 bit deployment. I'm not sure what this check box does, but it does not install a 64-bit Revit Program. Maybe its for future when it is available in 64-bit.