Replacement Amp For Audio Research Classic 60

Very pleased with my System which is Turntable based and consists of the following;

Audio Research Classic 60 Tube Amp.

Audio Research LS5 MKIII Pre-Amp.

Herron VTPH-2A Phono Stage.

ProAc Response 2.5 Speakers.

I have owned the ARC Classic 60 Tube Amp since New it has been that long. Scott Frankland formerly of MFA has changed all of the important Caps.

Fearful due to Age that I need to research a Replacement Amp in either Solid State or Tube form but here is the catch; It needs to fit in a Rack so the Dimensions should be 19" Wide Max X 8" (Give or take High) X 16" Deep.

ARC LS5 MKIII has Balanced Outputs but I can go to Single Ended since there is a Switch on the MK III for Balanced or SE. I am running it SE at present to the ARC Classic 60.

My musical tastes are Classic Rock and Folk with some Classical.

In my research the one that has caught my eye is the Pass XA25 but I am truly not sure how this would be with the ProAc’s. I would hate to buy this Blind. I also liked the Luxman 509X very much but I really do not need an Integrated. These two Models are mentioned to give an idea of Price Range also.

Any suggestions would be appreciated.