Welcome to Just Commodores, a site specifically designed for all people who share the same passion as yourself.
Just my 2 cents if interested, and I'm no suspension guru or anything, but my plans at the moment are for lowered springs (probably 30mm like you, but 50mm max) matched with Bilsteins -but I am after a more comp set up (without going for coilovers), rather than for cruising. The Bilsteins will be harsher as a daily (doesn't bother me so long as it sticks through corners). If I wasn't worried about increasing the damping, I'd be sticking with the standard shocks for a 30mm drop.
better shocks and springs will be stiffer but sway bars will give the best conering upgrade
G'day snips. If I can 'get away' with standard shocks I will. I gather 30 to 40mm is limits. So what is the front and rear sizes I should go for.