Wow, that's a lot :)
I'll do some research.
I'm going to buy iBasso D-Zero.
I don't know much about your amp, other than it is the entry level of that line.
Assuming it can push the 250 Ohm DT 880 Pro and you are OK with semi-open cans, it is your best choice from you list.
If you want a close can, it's difficult to beat the sound of a SRH 940.