I'd advise against a Summon Druid...you don't get the sheer quantity of pets a necromancer does, and, while they are pretty strong, I've found that they just aren't quite enough. now that said, I made a Summon hybrid, but there's not much else a Druid knows that can save you with only a few points invested in case your pets can't hack it.
This is, of course, purely my opinion.
