I moved from the States to Paris 2.5 years ago, and was faced with the same problem (110V gear running on 220V). Fortunately some of my equipment (Quad and Revox) is multi-voltage, no problem there. The rest is 110V equipment, Including two 200W/channel power amps. I simply purchased a 2kW 220V/110V line stabilizer transformer (~$200). You can purchase the equipment from www.eastwestintl.com or www.220voltappliances.com. The other thing to remember is, HiFi equipment in Europe, especially high end gear, is a lot more expensive then in the USA. Bottom line, bring your equipment with you and use a voltage stabilizer step down transformer to run it.
However, one thing to consider, and I learned the hard way. Certain US high end manufacturers (Krell for certain in the last ~10 years, and, I believe Martin Logan and others) put a frequency sensing chip on the power input circuit. This senses if you are running 60Hz (US) or 50 Hz (Europe) mains voltage (irrespective if it is transformed down from 240/220V to 110V and will not work if the power source is 50Hz. Krell in France charged me $180 to have my Krell HTS converted when I experienced this problem. Check before you leave!
However, one thing to consider, and I learned the hard way. Certain US high end manufacturers (Krell for certain in the last ~10 years, and, I believe Martin Logan and others) put a frequency sensing chip on the power input circuit. This senses if you are running 60Hz (US) or 50 Hz (Europe) mains voltage (irrespective if it is transformed down from 240/220V to 110V and will not work if the power source is 50Hz. Krell in France charged me $180 to have my Krell HTS converted when I experienced this problem. Check before you leave!