Yes that is the correct site for Rooster. Their shop is just down the road for me.
The secret with hiking pants is not to get them too large, they need to have a fairly tight fit (I wear size M). They do act like a wetsuit but they leave the top of your body exposed, hence the need for a dry top, which is slightly different to a spray top as it seals around the waist, wrists and neck and therefore keeps you dry during a capsize – hopefully!