Congrats on your decision to go natural! I am 3 months post, and though challenging at times, I love it, and it has been worth it.
I second the Shea Moisture line, and you can probably use a lot of the same products you used for your relaxed hair as long as they are "moisturizing." I am not familiar with the Good 2 Gro you mentioned, but a lot of products marketed to transitioners is just that--clever marketing.
Though once I began transitioning I definitely must say I bought my share of products, why not celebrate, right? Here are some great ones:
Shampoo-Keracare Moisturizing (no sulfates)
Organic Root Stimulator Creamy aloe (gentle sulfate)
Cleansing conditioner--Hair One olive oil (comparable to Wen, has light silicone in it). This is my absolute favorite!! I use this a lot, and clarify once a month with the ORS Creamy Aloe to prevent product buildup. I love how soft my hair feels with this!
Deep conditioning treatment--ORS Replenishing Pak (amazing)
Leave-in treatment: Giovanni Direct leave-in. I also use Tresemme Naturals conditioner (silicone free). It is a rinse-out conditioner, but I use it as a leave-in to help detangle. Both of these products have great slip, which makes it easier for you to detangle while your hair is wet.
Natural oils: My hair LOVES coconut oil! I use a little bit added to my leave-in and seal with a small amount of grapeseed oil, sweet almond oil, or olive oil. It helps to lock in the moisture.
I hope that this helps. These are my best products, but there are a lot of great ones out there. Best wishes in your transitioning journey!