I think you need camber kits on both.
Coilovers are more expensive at first, but they will save you from haveing to take your car apart again later on, because even the best lowering springs will eventually take out your stock shocks. Lower ride = more pressure on the shocks...
So I would say go with the coilovers in the beginning to save yourself the work later on.
Not getting camber kits is bad for the tires and it's not safe for the driver and all the other motorist out there.