Rechargeable AA's

Alright, stupid techy/gear question time...

What are your preferences for AA rechargeable batteries? I work in a studio environment and need to power a couple pocketwizards, and occasional location (within 1 block of the studio) work with an SB-800. Any brand preferences?

Side question. I'm familiar with NiCad, NiMH, and Li-Ion batteries and their differences, but I've seen a couple NiZn batteries lately. How do these perform? I know NiMH's big advantage was lower internal resistance which is good for flash recycling, how do NiZn perform? I know they have a higher voltage, but don't know about the internal resistance.

Again any actual experience with particular brands would be appreciated.
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~K