Which model are your speakers? I've had great success with an Eico HF-81 integrated on my EOS HDs. I've wondered how the Manley Stingray, another EL84 tube based integrated would do with them. They can definitely been found used in your price range, have sub out, and are switchable from ultralinear to triode.
I also really enjoyed my VAC Avatar Super with the EOS HDs, but this is out of your budget.
I also really enjoyed my VAC Avatar Super with the EOS HDs, but this is out of your budget.