Ultimate Orange & Xendadrine are basically the same thing...main kick coming from ephedrine & caffeine. Each have a few different indredients from the other, so either of those or another EC/ECA stack should work for you if you're looking for a little pre-workout boost.
AST Research's Dymetadrine Xtreme states that they include "adrenaline precursors" and some kind of special "neurotransmitters" or some B.S. like that, but it's basically just the same as the others.