That site has a bunch of fancy javascript added to make the selection slick. (It is also "fail-safe" so it still works if javascript is not available.)
You could do the same if you were a whiz with js, or you could hire someone to do it.
You could get a similar "expanding on hover" result without the smooth sliding by applying CSS to the attributes, if you preferred radiobuttons to dropdowns. CSS3 techniques would even allow some if not all of the smooth transitions, but they are not widely supported by browsers yet.