Im looking to pick up some QUALITY AA rechargeable batteries. Also looking for a quality charger. I need something decent to power my speedlight, but I dont want to go Nizn or with anything that will overvolt it too much. I just got some LiFePO4 cells from AW (small manufacturer) that are working great in my triggers, but these are CR123 size. Any recommendations?

Main Requirements:
Relatively affordable
RELIABLE (I dont want cells dieing on me!)
Relatively low self discharge (So normal NIMH is probably out, maybe LSD ones?)