There are no equipment requirements anywhere in the game. DM is hard to get drops from- just keep trying. It will easily take many people dozens and dozens of runs to get anything good.
You do not have to get any gear from the previous dungeon to get gear from the next dungeon. Heck, you don't even have to complete a lot of them! (Aquila Dungeon's excluded.) Your chance to get any and all gear is independent of what you have got in previous dungeons. So in a word: No. Just keep at it you will get lucky one of these times.
Darkmoor wands seem to be more rare. I've only gotten it on one of my wizards. You don't need to have certain gear to get any drop in the game. Drops don't work like that. They aren't like spells, there are no prerequisites.
