NJ,

11.1 volts (3 Cell) is somewhat overkill. I would use more likie 7.2 or 7.4 (2 cell). They are cheaper for the same size as in the 11.1 version

Here is the regulator I use

http://www.fromeco.org/shop/shopdisplaycategories.asp

There are others, so I'm sure others will chime in also