Get a Class D with a tube input stage. I would look seriously at a used Rogue Hydra. You should be able to find it used for $1500 to $1800. Then roll in a pair of NOS Cifte or Mullard long plates and be shocked at how much it sounds like a tube amp. There are more expensive options from AVM and others but the Hydra is a tremendous value and fits your budget. I have owned one for six years and it is an amp I will probably never sell. It won't be exactly the same but is a reasonable facsimile.
I am a dealer but have no affiliation with Rogue Audio. Just a happy owner.
I am a dealer but have no affiliation with Rogue Audio. Just a happy owner.