Two completely unrelated questions

Ok, first off, this one's on the topic of my odd case mod plan. Does the ATX formfactor force mobo makers to use a set distance from the P/S 2 connectors to the closest end of the motherboard, or will this measurement vary? I don't have much room in my desk, and would like to make a modular design so that it will work well with the next revision of my computer (next mobo).
Secondly, I used to have a set of four rechargable AA batteries that would give me about 4-5 hours of discman use, and only take an hour to recharge, and was wondering where I could pick up a new set.
TIA
-Ben