Yeah you don't want to get aftermarket springs and use the stock shocks.. the stock shocks aren't made to handle the more agressive spring rates of most lowering springs, plus they are not made to operate in the range of motion the lowering springs would put them at. You can "get by" for a little while when you get lowering springs, but you will eventually have to get new shocks. If you have the money, it is definately easier to do them both at once.