Hello Patricia,
Yes you will have to change the transformer to a 120V to whatever Voltage the bulbs are. You might be able to stay with the Euro base( guessing they are Euro base ), for there are a number of low voltage Euro bulbs availible here in the US. The best advise I can give you really would be to go to a quality lighting showroom and seek out their advise and guidance. They should be able to supply you with all that you might need to achieve your desire.
Andy
June 2008