One alternative to look at is Electronic Theatre Controls' "Source Four" ellipsoidal spotlights. I believe they have units designed for use outdoors, and also units with metal halide lamps. I don't know if the two features are available in the same unit.
These can give you long throw in conjunction with a lot of light.
Hey Solar, I checked out there website. Pretty inpressive. Couldnt tell if there stuff was more then damp location rated though. Suckers can throw some light though.
HP