I decided to add 2 squads to my Greatcoat platoon, nothing really ground-breaking, adding flamers to the basic infantry squads. With 6th ed adding grenade throwing to the mix I also added a grenade chucking lasman to the mix, also a guy with a Necromunda lasgun for variety:
So currently here's the whole platoon: 4 squads, platoon command squad with meltas and a special weapons squad with meltas.
Future plans include adding heavy weapons, either missile launchers or autocannons