Axel is right... there aren't many wrong ways to go, but your not looking for the easy cookie-cutter response. You want a tangible answer. So here is something you could use.
IMO, Necro is going to be better for you than Elementalist. Here is why: Soul Reaping is really, really powerful in PvE. Given enough mobs you are going to rarely have any problems with energy. Also, you won't have to worry as much about energy regen with SR. Though Elementalists have a great deal of energy, most of their useful spells are high cost too. There are skills that help you get around this, but it is easier to use Necromancer for your primary (not to mention you will have more variety in useful builds).
Now for your secondary class. You have a couple of solid options. You could go either Monk or Mesmer. Both are solid. the N/Me is great because using arcane echo can allow for higher damage output. Monk, however, might be a little more versatile for you. Monk has options. You could go the solo N/Mo route, the minion master, or even do a blood build. Monk can help with all of those. And since Curses builds rarely use the secondary class, you can create a good Curses build too.
Of course, you are going to run into issues with any build you use. None are infallible. That's the beauty of Guild Wars. So that being said, go with a class combo that can be versatile.
I hope that helps.
