Best Amp/Preamp Combo-10M, 15M, 20M

M as in Million?

The best Shindo preamp and amplifier(s) you can get that will drive your speakers. With that recommendation made, and since you did not stipulate a price range/limit for speakers or share what type(s) of music you listen to and the size of your listening room, I would recommend, in increasing order of price, the Auditorium 23 Solovox, the DeVore Fidelity Reference Silverbacks, and either of the Shindo Latour offerings. If you would consider vintage speakers and could find a nice pair of Altec Valencia 846A's (16-ohm version), that would be another great choice.

there are literally hundreds worth consideration. buy what you like.