It depends on your budget. You can't really go wrong with any Axiom speakers, however I do prefer some over others.
My favorites are these:
Bookshelf: M22ti
Tower: M60
Center: VP150
Sub: okay, I know, most people prefer the EP175, but I like the loudness and depth of the big EP350. Two EP175's beat one EP350, but if I ever own a house or an extremely soundproof place, I will purchase a second EP350.
I hear great things about the M2i, as well. They are apparently mini-M22Ti's.
Based on your size room, I wouldn't worry about any of these speakers filling it with sound. My M3Ti's filled up a 400 sq ft. room with a 70wpc Denon amp.
