What kind of car do you have? Regardless, your chance of bottoming out is determined by how low you make the car and the rate of the spring. The lower you go, the stiffer the spring needs to be to keep you from going all the way onto the ground or bottoming out the shock (destructive!)
As stated, Ground Control adjustable-heighth coilover sleeves are the best of their kind, they are make using Eibach springs and run about $300 or so. Or you can spring big bucks for threaded-body shocks with matching rate springs for $1K+.
PS--Camber correction kits will NOT prevent you from bottoming out! As their name suggests they are for fixing the issue of too much negative camber when you lower the car *substantially*
There is some built-in adjustment in the factory system the can compensate for a moderate amount of lowering, but a camber kit is never a bad idea. It saves your tires from premature wear. $300 is pretty steep, depends on what year/model you drive.
If you are on a budget, there are numerous good spring makers with fixed-height drop springs for well under $200 for a set.