Should I be exploring dbm files?

Yes, you should explore them. I don't think that they will prove to be the best choice in your situation though. They aren't relational and your data seems to imply that flexibility in accessing it should be a requirement. Just the same, a DBM would probably be better than your current scheme. It would also be relatively easy to implement.

-sauoq
"My two cents aren't worth a dime.";