I have a first-generation Intel Mac Mini (802.11g-compatible) that's connected to a last-generation Airport Extreme network. The wireless signal is extremely poor where the Mac mini is, I can barely stay connected. Would it be a better idea to buy an Airport Express, place it half way in-between the Mac mini and Airport Express, and extend the range of the 802.11g network? Or should I buy an 802.11n USB adapter and replace my old Airport Extreme with a new dual-band model (so the Mac mini can run on 802.11n and still have support for my older g-compatible devices)? Thanks.