Need suggestions on two channel amp for ML Aerius-

I am just getting started on this incredible journey and would welcome some good direction on upgrading my existing system.

Last year after drooling for years over high end gear, I purchased ML Aerius i fronts, cinema center, Mirage OM series Omnipolar rears and a Yamaha RXV1000 receiver with a Mirage Substrata sub. My video source is a Sony 40 SBR (really nice). The salesman was honest in recommending the yamaha and told me that I really should have separates but the Yamaha should do OK for a while (budget constraints). Its been fine until I recently noticed the ML's sound like they are wrapped in wet blankets. So i purchased a B&K 4430 to beef up the front. It is working quite well but now I recognize the need to go further.

I would like suggestions on a two channel amp for the ML's while using the B&K for the center and rears. Also what pre/pro for the system. Note that I would like to keep the B&K because I got a good price on it. Also, I would consider dumping the ML's if you think there is a really good speaker out there for great two channel music as well as great multi channel HT. All the while keeping in mind that I want to go only to the next level, not the top. I'm having fun with this and would like to savor each level of improvement in sound. Currently the ML's don't sound like a good full range speaker. They are weak on midrange and bass.

Thanks in advance for your thoughts