I think there has been lots of discussion about this in the Batteries section. I think you'll just have to use the batteries and see for yourself. I use Energizer e2, Duracell and SF123s with SF lights. I have used Toshibas and Sanyos also and would rank them in the following order:
Best to worst (in my opinon)
1. SF123 (very bright using them in SF lights)
2. Duracell DL123 (good consistent performer)
3. Sanyo(economical but does not produce as bright/white light as the first 2)
4. Toshiba (ditto)
5. Energizer e2 (Same as the Sanyos and Toshibas but costs twice as much)
I don't have the equipment for fancy tests, but just my eyeball opinion after using thousands of 123 size batteries with SF lights. (I have lots of other lights but for EDC, I just can't get myself to carry anything less than a SF and ARC AAA combo)
As far as cost factor, that's a different story, I think you can get Tekcell off Ebay for $1.35 each. Toshiba and Sanyos are cheap too, around $1.50. SF123s are about $3-$3.5 (guess you pay for the best)
I use Duracell DL123s for normal day to day use. Duracell Ultras only have different recovery characteristics (for use with flash cameras etc), voltage and runtime is virtually the same if used in SF lights. Not worth the extra cash. Hunt around and look hard, you can find them for less than a buck a piece)
