advice on what to buy

I am starting research on setting up home theater. I have a very large room - 22x37. walls are 10' high topped with a cathedral ceiling with a peak of 26feet. the flooring is ceramic tile. with the plethora of equipment out there I was hoping someone might give me some pointers to get started on my search.

How much power will I need in an A/V receiver for this large room. What level of equalizer or sound control will I need to help me tame this room from too much mid-range? what about echo with all the hard surfaces?

Speakers - I am leaning toward 5.1 but also support 2-channel music listening. Subwoofer - will I need a lot of power to fill the room? how much wattage?

thanks in advance!