Understand the recordings sound quality of either an analog or digital recording dictates the audio systems potential. Don’t believe loudspeakers are the most important system component, everything matters. A dedicated 20 amp power line or 2 depending on the complexity of your system should be the starting point. Room acoustics have equal importance but should be your last task as you dial in your system. Look for components that have a low noise floor and lack a "mechanical" sound characteristic, even some budget gear can achieve this. Don’t try to integrate a home theater system with your 2 channel system it will almost always degrade the SQ. Lastly know what your biases are and what you like, because there is not one unanimously perfect audio system.