Elucence Moisture Acidifying shampoo (only $12 for a liter) is the best shampoo I have ever used on my natural 4b hair. You can only buy this online unfortunately, but it lasts a long time since it's super concentrated.
For a salon conditioner I looove Kenra but it can get pricey. Lately, I've been using Dove Daily Moisture conditioner for the price and availability. Also works great as a leave-in/ moisturizer and smells really good.
Darcy's Pumpkin conditioner is amazing but for the amount and the price I run out too quickly using it on my thick bsl hair. But I highly recommend it if you can afford it.