Which ohm version of the DT 990 premium should I get?

After my Sennheiser HD 555s have basically decided to disintegrate entirely, due to the brittle cheap ass plastic for the cup frames. I have been looking at getting some new headphones and I saw the Beyerdynamics DT 990 premium on amazon, but I'm unsure of which ohm version to get. 

I feel like 250 ohm would be put to good use for a lot of things, but should I just go the extra mile and get the 600 ohm version and then get and a good amp like the O2 amp you guys showed?

The 250 ohm version is $245 right now on amazon while the 600 ohm is $332. 

If there are other headphones you guys think would be better for around the same price, I would like to know.

Thanks, Dan