Class A Amp to go with B&W 704's ?

I am thinking of getting into the world of Class A amps. Currently running an old Adcom GFA555ii with a GFP750 pre and some newly acquired B&W 704s. I have done some searching of the forum but have not found any recommendations for a Class A amp to mate with either the 703s or 704s. I am considering a used Pass X-150 or a Krell KSA-150 to pair with the B&Ws. Any experiences with these possible combinations, or any other recommendations to consider? Thanks for any input.
Both of those amps have a great reputation, I haven't sat in front of them, but at that price I can whole heartedly recommend Coda.