i don't know whether I explain the situation correct or not!
But this is in details:
we have a steel structure with 3 floors, a floor under ground and 2 floors above.
the under ground floor is parking + a room, and doesn't need wireless connection.
but the 2floors above!
each floor has an area about 220~240sm (m^2), and i need wireless in all corners of them.
each floor above the ground has different elevations (duplex)
about 120sm in one elevation and about 120sm with different elevation (higher height from the other one I mean).
all the walls are brick made, and has thickness about 20~25cm.
the ceiling also is concrete made and the thickness is about 30~40cm.
now the router is at the corner of the building in the grand floor (sometimes i didn't have signals even in the room exactly above the router!)
so, in this case!
with these Wireless N and Mimo technologies, I couldn't have wireless in all spaces?!
so if that's correct i should use repeaters for each floor, or two routers as you said!
But, I think this is not too much space...!
If the answer is no!
again, which adsl2+ wireless router you recommend?

before reading your post my choice was the Belkin N1 Vision...
hmm...?!
sorry about this much writings to explain the situation, that's because of my poor English and my architectural studies!