My Dad always used to say, "For 50 bucks more, get the top of the line."
Ok, he never said that. But I always pretend he did, and it has served me well, in those rare occasions when the top of the line is only 50 bucks more.
I'd always rather have unused space than run out. It's way too early to determine if 64gb is overkill. I'd rather be safe than sorry. Especially for only 50 bucks. Thanks Dad.