Mycorrizer : it‘s a myccelium that make a symbiotic relationship with your roots, the myccelium break down nutriens & provide it to the roots in exchange for Carbohydrates…
It‘s pretty expensiv but worth it, i don‘t think the brand really matter just compare the ammount of mycorizzer thats in the bottle to other brands ( i use powder, Never know about liquid culturs), spend for mine about 30€ in powder, last about 6-8 grows… reccomendet
Root Stimulater :
Not really needed ( you can make your own compost tea )
Also in my oppinion it only make Sense of grown organic since your miniral nutriens could damage the microbial life in your medium & you just waste money