That case should be absolutely fine for your build, a 670 will fit nicely.
In terms of Cooling, other than the fact you want air being blown in from the front and from underneath, and air being sucked out the back and out the top, there is no real right and wrong.
It is also advised that you have more air being sucked out (provided you dont leave un-meshed gaps everywhere that will allow unfiltered air in to the case).
So, really its up to you what fans you want and where as long as you abide by the above. Just check the spec of the case, see how many fan spaces you have and what size they are, then search for some
For example, if you have 3 fan bays open (as in theyre not filled with the pre-installed fans), then go looking for some 120mm fans and just choose the ones you want.
Really though, you dont actually need any more fans than are supplied by the case, they should be more than adequate, but each to his own!
In terms of motherboards - with a case like this, getting a m-ATX would be a bit silly, it would be like buying a multi-story parking lot when you only have a mini cooper. Get a normal ATX board and youll have much more room for upgrades and should space apart your components better.