OK, keep in mind that the 7555s are CMOS. You'll be lucky if they will source 10mA with a 15v supply. However, you're on 12v, so expect less. You would need a 1K output resistor (or more) with a 7555.SgtWookie --> Its an 7555CM. Looks good, gonna give it a shot when i get some fresh 555's.
You would actually be better off using PNP power transistors with a CMOS 7555. They can sink up to 100mA, and their outputs can go all the way to Vcc(Vdd)
BJT 555 outputs can't get all the way to Vcc (even lightly loaded) because they have Darlington outputs. But for NPN output transistors, a bjt 555 will work much better at 12v.