Here's the instrument to use for that sort of lighting:
http://www.etcconnect.com/product.overview.asp?ID=20080 I believe they are approved for wet areas, as I know they are used in outdoor theatres.
The normal lamps are only rated for 300 hours, but they have long-life lamps also that are rated from much longer. Also, there is an HID version.
Edited to add: They look like they'd be horrendously expensive, but they're actually only about $275. (Edited again to add: I posted that before I saw your reply. That price is the incandescent version; I don't know what the HIDs cost.)
[This message has been edited by SolarPowered (edited 06-22-2006).]
