Help choosing ROM + kernel

Hi guys could you help me out with choosing a Rom and kernel that will not be laggy and battery friendly? I'm not play any games or something so don't need really high performance, there is too much roms and kernels can't test everything, thank you very much for helping :)

Help Choosing Phone

Hello,

I'm moving from IOS to Android in September. I currently have an iPhone 6 and I'm stuck between a few devices; The LG G4, Nexus 6 and HTC one M9.
Im mainly looking for a decent battery life and the reviews for each phone say different things! So i'd like your opinions and what you'd choose?

Thanks in advance!:)