Pioneer S-1ex amp and pre: what i need?

I would like to improve the listening of Pioneer S-1EX, S-7EX and S-2EX. Now I'm using the SC-LX90 Susano European version of the sc-09tx. I read reviews about the very interesting coupled with the Bel Canto. Can someone help me on a choice? Your opinion about pre section of Susano? Thanks to everyone