Nashbar has both the Superflash and the LD-1000 on sale right now, if your LBS doesn't have them.

For batteries I greatly prefer AAs over AAAs, especially since I use rechargables. Rechargables are lower voltage (and hence give a dimmer light) anyway and with AAAs I'd worry that I would have to swap batteries more often than I want to, or I'd forget. With AAs, I swap once/week. I suppose this is a bigger issue if you have a longer commute and use the lights more hours/week.