New dual band wireless router suggestions

There seems to be a bunch of wireless interference at my office lately. ATT man said this, and I don't know if this means anything, but my wireless strength indicator bounces all over the place these days. I was told that a dual band wireless router may help (currently we have a dsl modem/wireless router in one unit). I've been looking at the Netgear n750 and n900. Should these do the trick? Any others that anyone would suggest in and around the $100 price range. TIA.