Aren't I lucky, as I found just the workout that ticks all those boxes. This standing arm workout doesn't have any repeats (i.e. all exercises are different), uses only two dumbbells and can be done ...
Lie flat on a bench or the floor, your knees bent, pushing your feet into the floor. Press a pair of dumbbells into the air, locking out your elbows. Lower the bells slowly until they touch your chest ...