3 channel amp recommendations for Arendal 1961 (4 ohm) LCR

Hi guys

I've been researching extensively but am unsure of a couple things.

Will an Emotiva a3 sound noticeably different to the XPA model that's twice the price?

On a similar note, will a Nord One nc252 3 channel amp sound better than the A3?

Could serious power i.e. Crown 1502 or above, or going all out for a Parasound a31 take my LCR to their very best sound?

I want the very best sound and will pay what it takes. That said, I don't want to waste loads of money for no/ negligible sound difference?

Anyone got lower sensitivity, higher impedance home theatre speakers with external amplification?

Muchos gracias chaps