It's really hard to answer this question without knowing what level of performance you are after and what your budget is. I def agree that speakers are the most important item in shaping your sound so invest there. Next comes source, then pre and finally amp in my experience.
If budget is tight, look at a good used integrated, Gryphon Diablo comes to mind but may be too much. Pass, Ayre, and many others make excellent options.
There are also many very nice DAC's that have good integrated volume controls and streaming capabilities.
My reply probably didn't help much but there are lots of paths to consider depending on what you're after.
Good luck!