For my home I have a Dyson vacuum. No filters or bags. Great consistant suction with the Dyson. The Dyson uses a vortex to separate particles out.
http://www.dyson.com/technology/rootTech.asp I inquired to Dyson about a shop wet/dry vac but Dyson does not make one. Too bad. The vortex idea would be the perfect solution.
-Don