The Fenix L2D Q5 is probably the reigning champ for most light + longest runtime on 2 AAs. See selfbuilt's review here: http://www.candlepowerforums.com/vb/...d.php?t=210904

Bigger picture: it sounds like all you really need is a higher-capacity battery pack. Why not spend your money on that? There's 6000mAh C-cell NiMHs available, for starters.