i would get coilovers so you can adjust the height to whatever you want. ground controls are good. coilovers are usually only about $100-$150 more than springs (per set of 4). i heard skunk2 and neuspeed coilovers are good too. look for ones that are made from T6061 aluminum.
coilovers naturally ride stiffer/bouncier than just springs because the springs in the coilovers are shorter, but you get to adjust your ride height, and accurately balance your car if you are going to do any autocrossing.
stock shocks should be ok with a 1.5" drop (whether with springs or coilovers)...but they will wear out faster because of the increased heat generated by the shorter/stiffer suspension. stock shocks are filled with fluid, while aftermarket shocks are filled with gas (so they arent susceptible to alot of heat build-up, making them last alot longer)