" 4300, 5000, 6000, 8000 "
These numbers would be options for color temperature:
4300 yellow, 5000 white/yellow, 6000 white, 8000 blue

Blue is the most attractive color, that explains the popularity.
White is claimed to be the brightest. Yellow is best for fog, rain, and dust there being less light dispersion/ back reflection, Fog lamps on Euro cars are yellow.
So, if your night driving is only in clear dry weather go for the 6000. For general use go for the 5000, it may give slightly less lumens but your visibility will be better when you need it most.
If you are buying for bling, go for 8000.