while i realize you may be headed in another direction, the pro series of the ivac units accomodates a tools and collectors of either 110 or 220v. a 110v powered tool can activate a 220v DC. and a 220v tool can activate a 110v DC. the Pro system seems to be pretty flexible as this indicates:
http://www.ivacswitch.com/default.action?itemid=57
just my $.02.