Can anyone recommend a great tube preamp that also has a headphone out?

Check into the Rogue Pharaoh,  it's probably got all you ask for and more. Has a great headphone out! IMO. it's right in your budget brand new.

“...But HOW does one get "spousal approval"

Sometimes its much better to ask for forgiveness later than ask for permission first.

PrimaLuna Dialogue Premium $3100 new, you won't regret it!

I use the Linear Tube Audio MZ2 solely as my preamp today, the best I’ve ever owned.  It not only has a headphone output, it is a premier headphone amp.  Check the many reviews.  Most buy this for their headphones.  I’ll be dipping my toes into headphone usage soon. I do a lot of late night listening and headphones will be the answer for not disturbing the wife.

PS Audio BHK Signature Preamp