Get a Fiio E10. It can easily drive 250 ohms. Added, it only costs you around 60 bucks on Amazon. FiiO DACs are great with Beyers! I never went wrong with FiiO's.
Go for DT990. My nerdy friend uses it, and it's awesome. Make sure you also buy a decent amp like Fiio ones along with it. Or else look for other low impedance headphones.