Yeah, the external battery thing was one of the perks I saw for getting the Tascam.
Not really seeing anything else that makes me want the h4n pro over the Tascam. It's going to be another month or so before I have to choose though, so maybe there'll be more info in the next few weeks.
Another idea would be to look through stock footage and just get a couple shots edited together that make it look like your character is flipping through. You can add music or VO for commercials or documentary type shows. You could probably find some pretty cheap stock that works for what you need.
If that's out of your budget, go ahead and shoot your own material. At the very least it gives you practice working with your crew if you haven't worked with some of them yet.
Definitely agree with Eric.
While I don't have practical knowledge, I have been researching this for quite some time. Lenses will outlast your camera. Camera tech changes constantly, lenses not so much. Make sure you invest in a quality adapter, too. You're going to need one with pins to connect an autofocus lens if you ever do gimbal work.