I got lucky one day and bought a commercial Nilfisk Whisperclean tank-type vacuum cleaner. They're made in Belgium and one of the few listed for asbestos cleanup. The uses a hepa filter and a disposable bag. The replacement bags are something like $9.00 a piece, but they hold a lot.Are you sure it's the filters I have had some vac's that just leaked. That's the reason hepa vac's are required for lead cleanup.
That said I use regular filters in craftsman and a small home depot special and do not have problems.