Really good speakers are very expensive; I would stretch as far as I could on a preamp; Audible Illusions for example; I've had mine since they came out, and it's been trouble free. I replaced the electrolytic capacitors recently to freshen up the sparkle.
Dollar per dollar, nothing has a bigger effect than the pre-amp. The most expensive speakers in the world will give you lousy music if you don't have the right electronics.
https://www.stereophile.com/content/audible-illusions-modulus-3a-preamplifier-page-3