Since major S.Fs come from Europe, it would be cool if you add these (my opinion)
- Alpha Group (Russia, just like other S.F. you already added)
- G.I.G.N. (France, could be something like a tactical loadout)
- Col Moschin (Italy, since they are paratroopers it would be cool if you create a parachute but with a web gear whit more slots than others)
And i don't have any other idea for now, hope this can be useful!