For the documents you are scanning in, how often do you really take advantage of the features Perforce gives you? I do something similar (check out the Fujitsu ScanSnap for an inexpensive 2 sided sheet feed scanner), then OCR using Acrobat. Acrobat has a catalog feature to make all pdfs searchable, or something like google desktop allows them to be searchable. I scan in all my bills (that I can't receive electronically) and then shred rather than save them in a box.
But back to my real reason for writing. I do all this with just a directory hierarchy. I'm not sure what is gained by using a revision control system for things like bills, etc. that don't tend to have revisions. You get one per month and that's that.
Thanks, nice to see others think the same way.