^ like the High Volume he already is
I would suggest looking at Ergonine, added to HV you will get a whole lot of effects beyond what you are looking for, on top of the studied dose for TMG, Creatine Anhydrous, and Hydromax.
HV has Taurine included, though it is so cheap that if you wanted to add more in you could, some guys prefer it in the 3-5g range (though usually when trying to avoid cramping or electrolyte issues)