maybe a floorstander?

should I be looking for a floorstanding speaker instead of my two-way stand mounts?  here's why I've been thinking this way, my room is 20'X14'X10' ceiling where I sit and listen and on one side is a 6' wide hallway (which in essence makes the room 20'X20'X10') that continues another 20' down to our front door.  also have open walkways that lead to kitchen and living room.  listening area has acoustic treatments behind speakers, full thick carpet, two chairs and a couch which is 6' from the back wall where we sit.  speakers front baffle are 5' out from front wall and one speaker is  2' from side wall and the other is open next to the hallway.  I do have one 12" sub.  don't get me wrong it sounds pretty good but I think I'm wanting more of a larger scale sound.  I'm thinking the room area is just to big for my set up. if you count the open hallway with the regular size of the room my calculations are 5200 cu. ft.  I imagine that the kitchen and living room areas come in to play also because of the open walkways into them from the listening room.  sorry for being longwinded, just trying to explain best I can.