Are Pass Labs amps probably the best ever you can buy ?

Steve McCormack’s new amps and preamp in my opinion are better.
www.smcaudio.com. 
Sanders sound Magtech.

LUXMAN IS ALSO GREAT

there are a lot of great amps.

like ice cream, too many flavors!

Not even close in my experience. 

Better value and better sounding than the Nakamichi PA7 [Pass designed] amp is the Usher R1.5 which is also a Nelson Pass design[a Threshold Stasis 200 copy].
The SIT 3 might be the best sounding of all the Nelson Pass designs but you would want to compare it with the Bakoon amplifiers which have a somewhat similar approach.The Bakoons are the best sounding  SS amps I have heard .Not quite Kondo Ongaku quality but getting there.

Is the Giant Killer Belles Virtuoso amp on the market yet ?..

I would say they are in the "team photo".  So yes, among the best.  Great resale, sound, and support.

Love my 250.8 and XP22.