ok well first set out how much youre willing to spend. because with what youre trying to do the cost can easily get up to $4000+
first start with your speakers. if you just want something 'better' than what you have 2-ways will be fine. if youre after the best SQ them you might want 3-ways. remember that the correct tweeter position can benefit the SQ of the system. in a 3-way the midrange will have to be positioned as well. at the end of the day, in general the 3-ways will cost more than the 2-ways.
the problem with speakers is that they all sound different, and everyone will hear them differently. so its hard to recommend you some brands. but try to listen to the better brands - hertz, focal, dynaudio, DLS etc - that will help you make a decision on what will suit you.
once you have your speakers you can decide on what amp you will need to run. deciding on whether to go active or passive will influence your decision here.
if you go passive all you will need is a decend 2ch amp, somewhere between 100-150 watts per channel, depending on the speakers.
if you go active it gets a little more complex...
for a 2-way active, you will need a 4ch amp. for 3-way active you will either need a beefy 6ch amp, or run two amps, a 4ch and a 2ch.
so its best to first decide on how much youre willing to spend, and how good do you want the system to sound, because it can get pricey very quick