What McIntosh Amp With Thiel 3.6 Speakers?

My current main system has a Mac MC-150 Amplifier and Thiel 3.5 speakers. While I enjoy the sound of my system; I've wanted to upgrade to the larger Thiel 3.6s for some time. Not only are the 3.6s a newer model; but from listening several times, I've concluded they have deeper bass and a somewhat more balanced sound. Now that I have the means to make this upgrade, I'm having some doubts if my MC-150 can properly drive the 3.6s. I would appreciate some feedback regarding a suitable Mac Amp to pair with the 3.6s. I should also mention that I mostly play classical and pop music at low to moderate levels; and my listening room is approx. 20 feet wide and 17 feet deep.