Its good you have a budget. That at least is a start. Now you need a plan. Without a plan you are toast. The advice you're getting so far for example, you will find yourself with WAY too much in speakers and nothing left over for when you discover how important things like interconnects and cones and room treatment are. Whereas if you start out with a plan that includes all these things then you won't believe how much it helps with all the decisions that come to follow.
I have to take some time to explain this because I know from experience hardly any of the supposedly helpful people around here have knocked it even though they have never tried it. So might want to keep in mind what I am about to say comes from both respected sources like Robert Harley but also has been proven to work by me personally in designing and delivering several complete systems the owners of which are all pleased way beyond their wildest dreams.
No system of any price (say again, ANY PRICE!) comprised of just speakers, amp, and cables will ever sound anywhere near as good as a much less expensive system comprised of a full complement of carefully selected tweaks and accessories like power cords, power line conditioner, Cones, rack or Shelf, room treatments, and tweaks like audiophile fuses, etc. A few thousand dollars in these will make much less expensive components far outperform much more expensive components. Obviously the only logical thing to do is include these in your budget from the beginning.
That's what Robert Harley recommends (search for his book) and that's what I have actually done. Anyone recommending otherwise my question to them would be: But is that what you did? And the answer will always be no.
Now realize Robert Harley devoted a whole book to this, so consider this just the first thin skin on the onion. And I know this is far outside the mainstream but again, its been tested and proven to work. One reason I think it works so well is it forces you to think carefully about what you really need. To wit, what you really need is:
1. One or more source components.
2. Amplification.
3. Speakers.
4. Wire.
5. Room.
That's it. On the face of it, 5 things, 20%, that's $2k per. Now that is exactly what I have done and know it works. But I also know there are people who have never tried it nor heard of anyone who has nor even heard a system done this way who despite all that no knowing are just chock full of contrary opinions and will adamantly explain why what they really don't know anything about cannot possibly work. Oh well.
Go with me here. So the budget for amplification is $2k. So here's what you do. You go shopping around to as many stores as you can find listening to everything you can find in the way of amplification within your $2k budget. That means you listen to pre-amps and amps, you listen to integrated amps, you listen to receivers. If you think for even one minute you might want the typical 5.1 home theater setup just go have a listen. You will drop that idea like a hot rock. (Or if not then you are hopelessly disinterested in sound quality, and I wish you the best of luck!)
Then while you are at it you go and listen to as many different speakers in the $2k range as you can find. Full range, bookshelf, whatever. Listen to subs if you want but I'll tell you right now there is only one way to do that and its not one sub - or even two- but if you do listen at least remember whatever the sub costs comes out of the speaker budget and nowhere else!
Then while you are at it you go and listen to as many different interconnects, speaker cables, power cords, and power line conditioners as you can find. Just remember, all those combined cannot add up to more than your $2k budget!
All that and still barely scratching the surface. Cannot stress enough, if you want to get the best sound possible for the money read the book, make a budget, and go and listen.