You're gonna have to make a choice there... All 3 of the options you want go below the radio... and there is only room for 2. They replace the "garage" with a double-DIN dash piece that will house 2 options or one with a pocket below it.

Last I knew the DVD system is not going to be available till spring time.

I'd say get the DVD and the MP3 player, as you can always dub your cassettes onto CD's if you really like.

Keep in mind, if you get the cassette player (or MP3) and the DVD system, you can always get a trunk mounted CD changer as well.