The Classe CA-5100 had been discontinued ages ago like some 15+ years ago. It's impossible to get it brand new. The seller must have lied to you. The Classe CA-5100 was an old amp or I would say an older Classe Delta series amp and was an entry level five-channel amp from Classe back then. Just like Audiotroy said above that older Classe amps are on the warmer side of neutral and might be suitable for your Focal since the Focals are analytical sounding speakers and tend to be on the lean & brighter side and are very forward.
The other two amps (Parasound Halo A52+ and Anthem P5) are new and current model amps.
For your Focal speakers I would get the Parasound Halo A52+ amp since this is a rich full bodied sounding amp and tonally on the warmer side of neutral. I would avoid using Anthem amps for your Focal speakers. In general, I am not that impressed with Anthem amps, their HT pre pro such as the AVM60 is awesome with its ARC2 room correction and is a bargain at $3k brand new.
The other two amps (Parasound Halo A52+ and Anthem P5) are new and current model amps.
For your Focal speakers I would get the Parasound Halo A52+ amp since this is a rich full bodied sounding amp and tonally on the warmer side of neutral. I would avoid using Anthem amps for your Focal speakers. In general, I am not that impressed with Anthem amps, their HT pre pro such as the AVM60 is awesome with its ARC2 room correction and is a bargain at $3k brand new.