This won't be what you are expecting but that sounds like a perfect amp for some AKG K1000 earspeakers, which you would use not with the headphone input but with the speaker terminals. Originally they retailed for about $1000, but Headroom (headphone.com) took out the remaining stock from AKG at one point and sold them for about $500 so there should some people who sell them around that price. They don't come around much and on balance, when they do, they usually are a bit higher in price.
They need about 10W (because they are so insensitive) but I think they are wonderful. To me, they are the best headphones I have ever used/heard (I have heard a few generations of top Sennheisers, the Beyerdynamics, the Stax phones up to the top end, the top Grados, and others and I have never found a pair I'd rather have than the K1000s. They are not completely quiet for the person sitting next to you on the sofa (because they are more open than open-ear cans) but they are fine for 'apartment living.'
They need about 10W (because they are so insensitive) but I think they are wonderful. To me, they are the best headphones I have ever used/heard (I have heard a few generations of top Sennheisers, the Beyerdynamics, the Stax phones up to the top end, the top Grados, and others and I have never found a pair I'd rather have than the K1000s. They are not completely quiet for the person sitting next to you on the sofa (because they are more open than open-ear cans) but they are fine for 'apartment living.'