I recently got a new camera and a Sunpack 383 hot shoe flash. This is my first hot shoe flash. I willbe using it for about 2 to 3 dozen indoor shots at local graduation this weekend (they have a reception inside after its over outside). I also plan on using the flash for a wedding recepetion in 7 weeks. Would I best be served using AA rechargeables or getting an external battery pack and if so which ones should I be looking at. At the weddinfg I figure I might need to take 150 to 200 shots with it.