Filter And Search

I'm trying to accomplish the following:

- allow my customer to go to a devoted page and fiddle with parameters (price range, dimensions, other customer parameters) to filter products

- allow my customer, once in a particular category, to filter products therein by (more or less) the same parameters

Whats the right combo of tools/add-on/options/etc to accomplish this?

This sounds like the case of setting up and using appropriate filters