Ceiling Panel Recommendations

Hi. I tore down a closet in my new house to make my home theatre room bigger by three feet. Its now 13x19', has a drop ceiling, and uses 2x4' panels/tiles. My wife and I discovered that the panels we already have aren't sold at Lowe's or Home Depot anymore so we've decided to replace them all. Any suggestions on the kind to use? Luckily the room acoustics aren't bad to being with. First reflections are my worst problem and they aren't that bad. Standing waves don't seem to be much of an issue either so I'm thinking really cheap on the ceiling panels. Lowe's has 45% sound absorbing panels for only slightly more than their regular ones. Will that be good enough or will they absorb random frequencies and throw off the sound balance? Thanks!