It should work fine with the same SSID etc on the 2.5 and 5ghz.
Apparently some N devices can get confused when they can see the same SSID on 2 different frequencies but most work with the latest drivers etc.
The only thing id say is before you go to all that bother, try it on standard with everything going though the superhub. Ive got my pc running N on the other side of the house from the router on with iphones, a printer and an extra laptop running G at the same time and I still get 50mb on the N machine without any issues!!