Any Audio Research Reference 610T Owners here?

Hello all,
I'm hoping to gather any advice from ARC 610T owners on this forum. I'm awaiting delivery of a pair right now and I'm hearing they can be delicate with regard to power input and that it's tough to get matched octets of 6550 tubes for them. Any suggestions on suppliers, brands of 6550s or using KT88s? Are there any problems I should watch out for or mistakes you could keep me from making?
you should also beware of the fact ,listen to the audio for an hour before you would left the house , you will NOT power up a poweramp like the 610T . That's why I bought
a SS poweramp .I 'm sure I 'm not the only one , my audiofriend replaced a beautiful sounding REF 300 by the Boulder ( also not bad sounding ) , for the reason I mentioned.
Great amp in the winter plenty of heat in the summer wear a bathing suit.
I email to ARC, he reply and said that KT120 cannot be use on original 6550C unless upgraded power supply. I just bought a mint ARC601T with only 122hrs in it, i have a Hansen Emperor 6ohms, which connection to the amp ohms i should use?
I replaced Krell FPB600.