Personally I'd go:
Eoin Morgan (Middlesex)
Moeen Ali (Worcestershire)
Sam Billings (Kent)
Jos Buttler (Lancashire)
Alex Hales (Nottinghamshire)
Chris Jordan (Sussex)
Tymal Mills (Sussex)
Liam Plunkett (Yorkshire)
Adil Rashid (Yorkshire)
Joe Root (Yorkshire)
Jason Roy (Surrey)
Ben Stokes (Durham)
David Willey (Yorkshire)
Mark Wood (Durham)
Willey offers more in T20 than Plunkett for me, but then I've never really been a fan of Plunkett. Jordan IMO shouldn't get near the squad, just because he bowls the odd decent yorker doesn't make him a good player and Billings is just damn right unlucky, definitely good enough for internationals but the rest of the team are on fire at the moment!