Choosing headphones for UR-RT2

I’m considering investing in the UR-RT2, so my question is among these headsets, wich one might be a good match for mixing and mastering pop/rock/acoustic/vocals/orchestrals with UR-RT2? Studiomonitors are not an option for me right now.

Worth mentioning that I do not own a headphoneamp yet, and I’m curious how far I can stretch it with this interface without having to purchase a headphoneamp in addition. The UR-RT2 seems to have fairly decent headphoneoutput (100 mW + 100 mW, 40 Ω).

Shure SRH1840 65 Ohm
Sennheiser HD660 S 150 Ohm
Neumann NDH20 150 Ohm (closed back)
Beyerdynamic DT1990 250 Ohm

I know there’s a ton more headsets I could’ve added to this list, but based on a few days of research, these ones are among my top choices.

Does any of these stand out as good choices for the (probably questionable) setup I am aiming for? Or are they all bad choices until I get an amp in addition?

I’d recommend the Sennheiser HD660, I use them and they are good.