Swapping lead acid battery for NiMH type

MrGrumpy

I have the following light set Knightlites and was thinking of swapping out the SLA battery for somehting more light weight and also possible switching out the MR16 6V Halogen lamps for possible MR16 12V LED type ? Just there are alot of folk making up there own light sets and some of them are very bright and light, a must have for my night time rides home after work.

Ok anyone got any links to suitable 12v ~ 13.2v NiMH battery packs ?