7 speed gear box is for the M5, 8 for all other F10's
the difference between the Sport and non is as follow:
Shape, the Sport has more of around shape not like the M5 but different to the standard one
depending on the year, i.e. Face lift or not and if your car has the added option of paddles you may not be able to add the Performance Pack, in my case I was able to do so for my 2011 M sport with Sport gear box as well as paddles, I know that this not possible well as off last year to add the Performance pack for 2013 cars with sport gear box and paddles.
Gear ratio is different with the Sport verses the normal auto.