There is a very large hunting/fishing chain in the USA, called "BassPro"
They sell them for $100 + tax. They usually stock spare bulbs and battery packs as well.
The Basspro shop in Orlando sometimes stocks the 240v model, so you might be lucky with the shop you try.
http://www.basspro.com/servlet/catal...=SearchResults From this link, you will be able to find store locations.
As to the voltage difference, one of these:
http://www.maplin.co.uk/Module.aspx?...19413&doy=10m9 will be ideal. There are various sorts available, sometimes cheaper. As the maglite uses very little power to charge, there's no problem