[Q] Need help root and rom topic

Hi.I always use rooted phone and custom rom.I bay sgs2 few days ago and i did not fint my mark of kernel.Everyware is something like x4k xw ...
Mine is adroid version 4.1.2
basebrand version i9100xxms2
kernel version 3.3.31-1156082
dpi@DELL175#3
SMP PREEMPT

And question is some easy way to root and what rom you prefer?speed,battery,stability=what rom?