not sure what tz3 stack is , but ZMA is a decent supplment. its' just zinc and magnesium, with B12 (I think) too. Zinc helps make sure the body can produce natural testosterone levels. So if you're already naturally peaked, ZMA isn't gonna do anything real amazing.
it does help you sleep soundly at night though, so if you have problems staying in a deep sleep for 8 hours, try ZMA at bedtime, with no dairy an hour before or after you take the ZMA.
Also, you'll get some pretty wild dreams on ZMA because you're in a deeper REM state.