Quick Recycle Power Unit for SB900 & D700

[bear1155]

I am looking for a power source for flash units to use on my D700 and D300 . I have both the SB800 and SB900 flash units. I understand the SD-9 only works with the SB900.

I am looking for a unit that provides very fast recycle times and is portable... Is the SD-9 the best bet for me, or are there others that are faster/better?

Thanks for your input. Regards, Lance