I've had an Ibanez GRG270B (GIO) for about 2 years now and I'm looking to improve. I have a budget of 700€ (max), which is about 850$. I play mostly metal, and also some classic rock, and I'm looking for a guitar that can handle both. My only restrictions is that it doesn't have Floyd Rose nor 3 Pickups.

From what I've been looking so far I've liked the LTD EC-401, the LTD EC-401VF and the Jackson DK2T Dinky.

Between the LTDs I'm still not sure if I would go for the EMGs (because of the lack of versatility) or the SDs (because I'm not sure if the JB can handle metal, and obviously the Jackson has the same issue).

So, if you could help me to chose between these three or even suggest another one, I would appreciate it.

I would also like to know if there is much difference between Grover and Die-Cast tuners, and also between Graphite and Ervana Compensated nuts.

Ec-1000 with the SD's in them, it can DEFINATELY handle the metal.
Agile 2000 2ts
ESP LTD Eclipse 1000, ASB
Crate GTD65
Peavey Vypyr Tube 60
The EC-1000 is 800€, so it's out of my budget, but I think the EC-401VF is similar to it, isn't it? At least it as almost all the same specs..
Grover vs. Die Cast tuners...

Grover are a quality brand of tuners. Die Cast is just an off brand.

GraphTech vs. Earvana

GraphTech Tusq nut is for tone and tuning stability.

Earvana, I can't figure out anything about it except its supposed to be better for intonation.