Everybody sells Vortechs - Nobody sells Tunze. Most Vortech classifieds start with "Newly replaced wetside" or "Just back from warranty repair." Just my $0.02, but not sure what the deal is, removing something from my tank to send in for warranty repair is a real PITA.
Personally, I think two small Tunze's, would be a nice fit, perhaps non-controllable 6065's or controllable 6105's.