Hey, I'm no expert either so I just asked my local mechanic and he had my rear leafs re-set for around 100 bucks. They say they could have done the same for my front springs but I was able to buy 2" lowered off the shelf.
When they re-set my rears we were able to see diff in different positions before settling on exact look. had 3" taken off my rear. awesome. makes my ZD handle better too.