Entry Level Tube Integrated Amps

I think if I were doing this I would start with my speakers and go from there.  I'd figure out what sort of sound I like and what dynamics.  If my focus were to be with tubes I'd like it if I could find an open baffle (probably) or horn-loaded (depends on your taste) speaker or anything easy to drive.  Then a whole world of tube amps, integrated too, opens up to you, and entry level wouldn't cost that much.  When you start getting into high power things get more difficult.  

Definitely check Rogue. Not the most expensive but beautifully designed and built. Both their separates (especially RP-7 pre and Atlas Magnum III) and their Cronus Magnum III integrated sound fabulous!

I like what DeKay said. You obviously have efficient speakers. Years ago I fell in love with the sound of Audio Research tube amps in combo with Martin-Logan ReQuest ES Hybrid speakers (larger than my Sequel II's) but could never swing the bucks for ARC. After my Krell amp took a lightning strike, I replaced it with a Vincent hybrid power amp. Don't kid yourself; it is a hybrid only that it has tube input stages, none in the solid state output, and it does not have that tube bloom we love. Meanwhile resting in my basement was an iMan "Valve Amp" "headphone integrated amp that I bought with an iPad docking station that I got with it new for about $750 from Audio Advisor. Well, as things happen, I started using the basement space for business and needed a music setup. That amp is rated for about 8 wpc and had two RCA inputs and speaker output posts in addition to the headphone plug on the face. I had my 1970's vintage New Large Advent speakers re-coned and hooked the amp up to them with a "no longer using" non-Blue Ray DVD player and the system played music with a deep an wide soundstage that blew me away. I know there are several Chinese tube amp dealers on EBAY with power from 5 wpc on up, in various configurations for less than $500. If I were in the "place to start" wit tubes and care more about the music than "accuracy" I would start there.

I know you said integrated but you might want to try a modified Magnavox console amplifier.  Make sure it has the original or NOS tubes in it.  Look online at the usual places.  You could buy an inexpensive passive preamp to go with it.  It will knock your socks off!

the best sounding integrated amplifier I heard was the Line Magnetic 28wpc why?  Because are built with a great transformer.  Nothing else listed here has one that I am aware of.  We build audio components but nothing integrated.