Recommend a Preamp for me....

I purchased a parasound 2205A power amplifier which is connected to definitive technology Mythos 1 for fronts, mythos 3 for center, and 2 mythos gems XL for surrounds. i am in the process of purchasing 2 more mythos for surround back speakers so i can make it a 7.1 set up. The subwoofer is a SVS SB12 PLUS. I currently have the Parasound connected to a denon 3808 receiver. Many of you probably do not like the mythos line, but the reason why i chose them was because i heard great things about them if used for movies. I also liked the fact that they look high tech and they dont require much space.
Here's my dilema: I find the sound somewhat "bright" but not as bright as when i was only using the denon receiver by itself. The parasound amp certainly toned down the brightness a bit and i liked that because i tend to get ear fatigue. I would like to get suggestions as far as which preamp can help make the sound a little less bright than what it currently is (I certainly attribute some of the brightness to the mythos speaker line).
Second, i would like to possibly choose a preamp that can be upgradable in case new formats arrive such as 9.1. I will be buying a blu ray player with great DAC's such as the Oppo or a pioneer elite so i dont really care if the preamp has no HDMI inputs.
Let me hear what you guys have to say... thanks in advance!