Old or new gear

I have the QS mid monos. They have a built in bias led meter. They also have the option of using different types of tubes.You can't beat them for the price!

Although Jolida is made in China (along with Primaluna, Hegel, your phone, your computer, your shirt, etc), it's finished and tested in MD USA by smart guys. Very well made and there is nothing that comes close to these things in relative value that I know of. I had a 502P (with inexpensive factory upgrades) for years and it sounded magnificent and was fun to bias (although it didn't need it generally, I just liked messing around with the meter) and roll tubes through, and I only sold it when I found a single ended tube amp I liked.

  I concur with Mattmiller's post. But then, I am biased as the owner of many McIntosh components. 

I would look at Atma-Sphere amps. They are built very well and give excellent sound. A used S-60 or M-60 should be in your budget. I would call Ralph at Atma-Sphere, he sometimes has demos and units for sale at a significant discount (that's how I got my MA-1's).
He can also give you advice on what will work well with your speakers.
Bob

With your speakers and practice of listening at lower levels in a small room, you should have many choices and alot of fun ahead. Additionally, if you went with a fine integrated you wouldn't have to worry about matching the pre to the amp let alone the cable nervosa certain to strike. Some nice tube integrateds that are reasonably available pre-owned that would fit the criteria you gave regarding countries of origin: Cary SLI-80 F1, VAC Avatar, Leben CS300-XS, Audio Research VSI-60 immediately come to mind. Service is convenient and reliable and they would each comfortably mate with your speakers. Also, within your budget you could spend a few dollars on a dac that would potentially be more musically pleasing than the Behringer but YMMV.

Disclaimer, I am not a dealer but have I have owned alot of tube integrated through the years and have loved the synergies of each for different reasons with different speakers. The Cary is nice with a nice headphone section, remote, easy to change the flavors with all of the tubes on board. The Avatar I simply love. No headphone but the original el34 based unit is magical. Some had remote, some didn't, just ask the seller which one. Over the years, it evolved in search of more and more power to the kt88 and lost a bit of its graciousness IMO. The original Avatar was the evolution of the Matantz 8b reissues VAC built and the Avatar I have always considered to be the *b integrated that Marantz should have built but only VAC and Kevin Hayes could achieve. I have owned 3 of these (have one now in my 3rd system and may or may not part with it. its perfect condition and they are hard to find in perfect condition) and keep coming back. Killer phono stage, no headphone, VAC service is A+++ should it ever be necessary. The Leben, within its power limits, is amazing. I have owned 3 of them as well (have one now in my office). Nice energetic amp and punches way above its 15wpc rating. Bass boost and great headphone but no remote. The Audio Research is a very nice amp, especially for what they sell for used. Not as "tubey" as the 3 prior amps which for your purposes may or may not be a good thing. I presently have a GSI-75 in my main setup and I LOVE it. Audio Research service is terrific. Others I have owned but will not again: McIntosh 2275 tube integrated, Line Magnetic anything, I've had 2 I purchased pre-owned and I always felt I was on some strange drug that made everything happen in slow motion when listening to the LM Audio amps LOL. I've had a few ss Macs which were fine and solidly built, a Nagra integrated which was excellent but a letdown for the $ spent, a BAT 300xse which was a fine hybrid.

You have alot of options but I've always liked buying with the peace of mind that a strong service oriented company is there when you need them. McIntosh, Audio Research, VAC are terrific in this regard. BAT probably is Ive just never needed service for a BAT. Cary Audio may be different now that Dennis Had retired so I don't know. Leben and Line Magnetic is through Tone imports so I'm sure its probably terrific although if you buy used it might be tricky, especially if you accidentally bought something gray market. My Lebens have been rock solid. I would be very surprised if the Schiit pre is a perfect match with all of the amps you are considering and great 6sn7's are not cheap. Probably TMI. Good luck!