Similac formula

Does anybody know if Similac alimentum and similac total comfort are basically the age thing and would it be okay to switch ?

My 6 week old son has bad acid reflux which he takes Zantac for 2x a day he also is eating rice cereal in 1 bottle per day for it

He has stomach Issues and is allergic to the proteins in regular similac so he was put on similac alimentum but I’ve been hearing that similac total comfort is really similar,a lot cheaper and helps more when baby has stomach/gas/reflux problems

If anyone can help me with this it would be great thanks in advance !!