If you are not looking for Stimulant based PWO drink then the question becomes what exactly are you looking in your drink? From the top of my head I beleive you want a PWO with:
a) Some NO based products.
b) Stuff like Citrulline Malate, Beta Alanine, Taurine, Norvaline etc.
c) Loads of BCAA/EAAs.
d) Creatine of sorts.
My suggestion is why dont you save money and make potent PWO yourself? I suggest mixing the following :
Xtend/Purple Wraath
MAN Body Octane/ Geeen Magnitude
Bulk Products- NO, Citrulline Malate, Beta Alanine, Cissus.
This will make a product darn more potent than most stuff out there, will save you money...and also tell you exactly what works for you.
Plus that extra BCAA/EAA will help you through a real gruelling schedule.
Good luck.