You can probably get 2 500 watt halogens.........but I'd bring a 300 watt along in case it keeps overloading! Halogens are cheap but there are other types ( H.P.S. high pressure sodium or Metal Halite) that run much brighter with less usege.
The bad thing is you don't want to max out your generator, it will greatly shorten its life. Try to run at 75% of the amp rating. Honda's are very good. I've run the 2000 honda, and its very very quiet. We ran 3 - 500 watt halogens and a 250. Worked pretty good.