Which one should I use? And our there any major differences like how you treat each one? I'm kinda leaning towards using 1/3 peatmoss, 1/3 vermiculite, and 1/3 perlite

Bottom line - unless you are obsessed with fittings, toys and technology (and many are) organics can grow nearly as fast, just as big (if not bigger), better tasting and IMHO more potent buds. And they do this with very little initial investment, and are very forgiving of newbie mistakes.

I agree with the mogster... save your money and put it towards good lights.
Your soil mix would be good or go with PRO MIX.