Stylus is easy: any Penabled one should work. This is the one I have, and it's more comforable than the little nose-picker that's stuck in the Edge:
http://www.amazon.com/gp/product/B000085BDA

Battery is also easy if you get something like an xpal and use that externally (I can look up the exact number of the tip that fits, if you want, but not right now without waking my roommate). Internal may have to come from eNTouRage.