I've recently configured SRM 5.1 for a client and I did break out the page files into their own datastore (as well as the vswp files). In short, here's a link that describes the process: http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=2009324
Here's how I copied the page file template .vmdks to the recovery site: http://www.vhersey.com/2013/05/copy-files-between-esxi-hosts-using-scp/
Honestly, it's turned out to be quite a task. Yes, it saves bandwidth and time not replicating transient data, but at a price. The initial time to set up, especially for multiple VMs with different amounts of memory, is not trivial. Then, of course, the client should change their operational procedures for deploying replicated VMs.
As far as drive letters, when the VM comes up at the recovery site, it will look for the same drive letter. The recovery site page files are cloned from the same template the the protected site VM is using.