Don't give up just yet. Pay a visit to you're local Tractor Supply store and look at their sealed beam tractor lights. You can get them in 6 or 12 volts. I've measured the current draw on these lights at 2.6 amps for the 12 volt version. I'm working on a lighting system using one of the 12V tractor lights for a headlight and a trailer light for the tail light. I'm using a 5Ah sealed lead acid battery from batteries.com- Notebook Batteries | Laptop Batteries | Camcorder Batteries | Digital Camera Batteries
. So far it looks good, but I haven't done any night time riding lately so I can't speak to endurance.