NOTE: This is highly experimental and is showing a high failure rate in terms of targeting real location of server. Also worth noting that "change location" in Google does provide differing and proper organic results.
Proxy #1 in Miami, Florida Provider Serverpronto <-- High Failure Rate on location
Proxy #2 in Miami, Florida Provider Serverpronto <-- Moderate Failure Rate on location
Proxy #3 in Boca Raton, Florida Provider Verio <-- Moderate Failure Rate on location
Proxy #4 in Allentown, PA Provider INetU <-- Low Failure Rate on location