Biggest problem you are going to have is the initial rights to broadcast the movies change occasionally so today, movies from DreamWorks (not DreamWorks Animation) air on Showtime when just a few years back it was HBO (fyi, DreamWorks Animations contract expires in 2013 with HBO when first run rights move to Netflix).
Epix has first run rights with many studios such as Paramount, MTV, Nick, Lionsgate, & MGM. However, HBO, Starz, & Showtime all have sub-run contracts in place with these studios so it is more than likely a movie which is destined for first run on Epix will eventually find it's way to one of the others or their sister channels within a few years.