KR Audio Kronzilla VA680i anyone ?

I have listened to them and work directly with Eunice at KR.  I import KR tubes as they are the only ones left I know of that make a PX25 and the balance of their tubes are pretty great.  It sound like a crazy project and will require some modification. Those amps are amazing sounding.  Tons of detail and oodles of power.  
Let me know how I can help.  I can reach out to Eunice and Marek (KRs lead engineer) for you.  

I have not heard issues in terms of reliability on KR Amps.  I also have plenty of customers who are running 15+ year old KR Tubes that still sound great.  
Like anything, a few people run into issues but there are relatively few problems that I am aware of. I have found a little bit of bad press from about 11 years ago when they had some turnover.  Definitely not an issue now.