Wow, that pic is very useful!
Sorry for my ignorance, but still a little confused about what the 'm' stands for. The pic you linked has both micro and mini. You said it shouldn't matter as far as the case is concerned, as long as it is standard ATX. Will this make a difference for the PSU? The answer is probably right under my nose.
, also known as µATX (sometimes transliterated as mATX or uATX on Internet forums) is a standard for motherboards that was introduced in December 1997. The maximum size of a microATX motherboard is 244 mm × 244 mm (9.6 in × 9.6 in), but some microATX boards can be as small as 171.45 mm × 171.45 mm (6.75 in × 6.75 in). The standard ATX size is 25% longer, at 305 mm × 244 mm (12 in × 9.6 in).
Currently available microATX motherboards support CPUs from VIA, Intel or AMD.http://en.wikipedia.org/wiki/MicroATX