Amp recommendation for AKG K1000's headphones?

I recently gave into temptation & picked up a pair of AKG K1000's. I've wanted a pair for ages & with their retirement there was no time like the present. Now comes the interesting part of finding an amp that pairs well with them :)

But before making the leap into uncharted territory [for me] I was curious what amps might be worth an audition? To level-set -- ideally this will become a dedicated headphone rig, so the scope of this decision doesn't need to account for synergy with my existing front-end gear.

Thanks in advance for your consideration.