Great question hfmaxi, I dont know 100% that the focus ST pan wouldn't work. It very well could. I also found the Delete kit with baffles for the st! Link below.
http://www.mountuneusa.com/2-0L-EcoBoos ... -oc-aa.htm
From Project Ugly Horse (if you are doing this swap it has some really good info)
"The Miata pan had the obvious advantage of internal baffling, something that's necessary for track abuse. Baffles help keep the oil from frothing, reducing
the risk that the system will suck up an air bubble and end a lap to the tune of your $8000 engine mulching itself. I'm told that's important."
http://www.roadandtrack.com/car-culture ... e-part-xi/
I also think the aftermarket oil pans from Raceline would work too. They make an aftermarket wet sump and dry sump.

http://www.raceline.co.uk/products/part ... tegoryID=1
http://www.raceline.co.uk/products/part ... tegoryID=1
Can anyone confirm that the Focus ST pan will work with the NC miata transmission?