I'm looking at putting in some new speakers on my '91 Camaro. So far, I've found some Pioneer A-Series 4x6 and 6x9s that I like, and are the right size for my car. I'm not looking to blast the speakers or anything, so do I necessarily need to buy/install an amp as well? Also, do I need to purchase two of the Geek Squad speaker installation packages? Because its only allowing me one in my shopping cart on BestBuy.com Thanks!