With the digitals I would opt for a bigger battery. No less than 800 mah. 1000 would be better yet. Digitals use more battery than standard servo's. I don't know why Futaba doesn't bundle a bigger battery with this package. I would say go for it. You cannot get the digitals this cheap anywhere else. If they seem too much you can always buy 4 standard servo's. They are around 15$ each. Save the digitals for later. Either way you win. I feel this is a good choice.

Mark Shuman