rgallant:
If you go with a R/C hobby BEC add a small 5 volt fan on that heatsink, they are designed to to have fairly constant airflow over the heatsink, think heli's and airplanes fast moving cars.Lastly if you plan on using a dedicated servo controller later make sure the output wires will handle your maximum amperage. If not you will have to change them out. I use a Castle Creations 20 amp for my bot, and it is nice and easy to switch wires, I am not sure why they don't come with 20 amp capable to start with.
The BEC i linked have option to put a fan on top of it.
I'm wondering what are the benefits of using a dedicated servo controller. I assume they are used to smooth down the movements by using so called "ramps". I could buy the same BEC you got, and I'm sure I need more Amps if I'm going to expand the project later on.
zoomkat:
You can get inexpensive UBEC voltage converters on ebay. You can add a small diode on the ground leg of the 7805 chip like below to increase the output voltage to 5.7v for better servo performance.
Thanks for the tip. I heard UBECs cause RF noise am I correct?