Ben I'll go with Jason, it's going to be difficult to beat the pricing and availability for standard recessed lighting from the local big box stores and the sizes you are seeking are standard sizes that should be readily available in stock.
I went with Lutron remotely controlled dimmers throughout our house and have been happy with them, again, the big box stores carry them and they are readily available. We have 10 5" and 2 2" recessed lights on remote dimmers in our 25'x 14' media room and we really like how they can all or partially be dimmed with a remote control.
One suggestion I'll make is to have your lights grouped on different switches so that you can highlight different parts of the room, for instance I have our 'stage' end of the room (4 5" recessed lights) on it's own switch so that portion of the room can be dimmed or highlighted separate from the rest of the room. I have the 12 room lights on 5 separate switches so that we can vary the lighting in the room.
