Need advise

My wife is giving birth in July, but confused which brand of pampers to buy.I have researched brand like pampers,huggies,Mamypoko but still unsure which is suitable. I scared that my newborn baby to have rashes...? And also is it advisable to buy S then rather NB? Cause New born is up to 5kg where S is 3kg to 7kg.. *Ps: 1st time becoming father