After a long search I finally decided on Cherry picker as a product filter. It's a clean cut filter via product types and parameters which has a very stable performance. I'm a pretty advanced joomla user but when I decided to make my site multi lingual with Joomfish I new it could get complicated. This is when I really discovered the true quality of this product: the developer supported me as long as needed to get the product filter fully working in every language, for all 226 virtuemart products. He adjusted the module on the spot to be compatible with Joomfish. Support also helped me to get the included Breadz extension working with joomfish.