I used to own Confidence C1 driven by the Parasound Halo A21 (preamp Primare PRE30). Decent match indeed, but perhaps not helpful enough info for you, since I have not any experience with other amps from list. Pass X250 should be better, relying on price difference vs Halo A21. Plinius 102 reportedly has some tublike mellow sound character, which might be not the best match with slightly darkish Confidence C1.
Top new ontopic info, a few days old. A friend of mine, C1 owner for some 5-6 years (which means he knows well what is he talking about), recently employed Krell KAV-400xi on C1, saying that cheapo Krell almost blown away both double pricier Classe CAP-2100 and exotic vintage Sansui Alpha 907 integrades. Particularly in bass area, among other parameters.
Hope this helps.
Top new ontopic info, a few days old. A friend of mine, C1 owner for some 5-6 years (which means he knows well what is he talking about), recently employed Krell KAV-400xi on C1, saying that cheapo Krell almost blown away both double pricier Classe CAP-2100 and exotic vintage Sansui Alpha 907 integrades. Particularly in bass area, among other parameters.
Hope this helps.