I'd go Necron if I were you - better fluff, and an awful lot cheaper (and in my humble opinion way better looks compared to them ugly bug thingies)
And don't mind the people telling you how this race is strong or that races codex would be outdated - in my 40k group, there's successful Inquisition and Dark Eldar players, in the end it's all up to your strategy, and both nids and necs are forgiving to play, since nids are many, and necs tend to stand back up.
And don't mind the people telling you how this race is strong or that races codex would be outdated - in my 40k group, there's successful Inquisition and Dark Eldar players, in the end it's all up to your strategy, and both nids and necs are forgiving to play, since nids are many, and necs tend to stand back up.