Because it seems like you're an intermediate level player, I wonder if when you say "too much power" what it really means is you're inconsistent, tend to hit long, and/or maybe don't hit with enough top spin. I have this suspicion that if I were to watch you play, I would cite your technique as being more responsible for your inconsistency than your equipment. But if you're worried about too much power than you shouldn't use an oversized racket.
Generally speaking, flexibility equals less power. Also, smaller head size equals less power. A denser string pattern is generally believed to mean MORE control (dense string pattern, 18 mains). Thicker gauge string can also dampen power.
With that said, if maybe you need to hit with more spin to keep the balls in play, you may want a more open string pattern (16 mains).
How are you with weight? Do any of the rackets seem to heavy or light to you? Like Scott said, demo several rackets from Tennis Warehouse. All you pay for is shipping.
If you check out the rackets on Tennis Warehouse's website, they have power ratings. I guess you would want something with "LOW" power.