I'm using a Nikon SD-9 with my SB 910 flash
http://www.bhphotovideo.com/c/produc...tery_Pack.html
It's more than twice the price of the Bolt (the Bolt is a knock-off SD-9) but I've always gotten my money's worth sticking with Nikon gear.
Lighter and easier to handle than my old Quantum, although when attached to the bottom tripod mount on my D4 it makes the camera a bit awkward to hold, so best to keep in belt pouch.