Integrated Amp that goes well with Triangle Celius

I'm a new guy in this area.
I have never heard of those amps and I have never thought of buying tubes because it looks so fragile and hard to maintain. However, If you can convince me that tubes sound much better than Solid state, I wouldn't mind buying tubes.

I did some research on the amps you mentioned and I see a lot of compliments on Unison Research and Primaluna Prologue. Only difference between two is the price. Primaluna Prologue is more affordable. Can you specifically recommend me the models?

Oh my so many~
Thank you for your kind feedbacks even I'm getting more confused about what to choose.
Here's my some preferences that might help narrow it down.
I want the sound to be warm but very detailed.
I love orchestral music, especially violine and piano concertoes, and also sometimes listen to opera arias and jazz. Like I mentioned before, My budget doesn't allow more than $2,000 for amp and CD player. I wouldn't mind buying used ones.

Thank you again,
Chulhee

I'm just curious about the terms you guys are using, Bridged mode and Monobloc set. It sounds like I have to have two amps to do it. Can anyone explain me a little more with easier terms?

Ok. Having amps running in bridged mode is way too complicate to be my first project. I'm going to try something simple but decent enough for my lovely Triangle.

I'll let you know how it goes.
Thank you all for your advice.
Chulhee