No, it should be backward compatible. They say ATX 1.3 has a 20-pin connector and 2.0 has a 24-pin connector, but really it's a separate 4-pin connector that provides an extra 12V.
As for whether the PSU actually fits the case, I'm almost certain it's the same too.
Edit: This is confusing, posting in 2 threads
I'd reccomend you get the ATX12V (2.0) in case you buy a newer MB in the future.
Link:
http://www.google.com/search?hl=en&q=atx12v+backw...compatible&spell=1
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