If such a bulb existed, I'm sure someone would have discovered it for use with 1 CR123 primary... But actually, I can't help but wonder whether the easiest way to accomplish this might not be with a boost driver and some off-the-shelf ~5W bulb -- regulation could be a bonus!
Anyway, WRT throw, more throw requires a hotter filament and/or larger reflector. Since I assume you're looking at driving whatever bulb you use to the edge regardless, boosting throw is going to need a big reflector, so minimag mods need not apply. Probably a 26mm (p60-compatible) if not larger, so my question would be: Why 2xAA? You could put together a 2x17500 Li-ion / 3xCR123 primary light in practically the same form-factor, with better runtime and decent primary (3xCR123) performance, whereas the 2xAA is guaranteed to be disappointing on alkalines if you run out of NiMH.