You can also find an extensive library of headphone response measurements on the Headroom site at
www.headphone.com, those can be used to make a response file REW can import to use to derive some inital filter settings, but bear in mind that at the higher frequencies the locations of the peaks and dips depend on the shapes of our ears so the listen and adjust route is the only reliable way to get the correct settings. Applying filters within REW will certainly make all that a lot easier.