This is the setup I use for starting my Raptor 50 and Fury Extreme 90:
Power Sonic Model 12V, 7.0 Amp Hr
Sullivan DynaTron super hi-tork starter (12/24V)
Robbe 6mm Hex starter for the Raptor
Miniature Aircraft Pro Flex for the Fury
This setup easily starts either heli, and I get about 3 sessions out of the 12V battery before it needs a recharge. I switched to the Robbe starter as it fastens on to the DynaTron shaft directly, rather than using a starter cup pushed into the propeller rubber; this never seemed stable enough for me.
Now all tidy in a new flight box with an Irvine LCD Power Panel and electric fuel pump: