Good quality speakers are the place to start. The real trick in buying speakers is getting ones that really speak to you… you have get an emotional connection with. To do that… I really recommend listening to speakers… as many and as high end as possible. Even if you are not going to buy really expensive ones… it will show you the character you like. Then, you can slowly swap out electronics to best support the speakers you chose.
There are a number of strategies to music reproduction, like: really efficient speakers and low power components, inefficient speakers that are very accurate (ridged cones so they snap back quick… but require lots of power), electrostatic / planner… that reproduce sounds way into the high frequencies and impact what you can hear through harmonics. The major groupings have advantages and disadvantages…
I recommend Robert Harley’s book, The Complete Guide to High End Audio. It will show you the different classes of speakers… pros and cons, how to pick them out and get supporting electronics.
One more word about sound. Detail is one of a dozen sound characteristics that are important in choosing equipment. It is also probably the easiest to get and in doing so get an unlistenable harsh system. If I read highly detailed… without lots of additional discussion on how natural and warm sounding it is, with a low noice floor… I go running the other direction.
Getting a high end system does not require enormous amounts of money, but it does require education and lots of thought… then you’ll get an incredible system.