without turning this into a headphones v speakers debate i will have to respectfully disagree with the above post because detail isn't everything with regards to sound presentation. It is true that speakers are much harder to consistently match or better headphones because of room dynamics and generally speaking, price. However, speakers offer several things that headphones can never match, viz. soundstaging in a more "realistic" sense. For me personally, i will and do choose my modest desktop rig of some decent polk bookshelves powered by a marantz 1060 over headphones because they play loud and throughout the room.
If we are talking about sitting down and critical listening, then as long as the presentation of headphones vs speakers isn't a factor and we're talking about detail per dollar and consistency in any given room, then headphones are superior. This isn't to make you shy away from speakers by any means but to alert you to the different expectations you should have.
That being said, i second the suggestion to audition. I also recommend checking out various internet venues with generous return policies (perhaps even free return shipping as with Aperion on all speakers and av123 on their xls bookshelves). And also, look into used.
Concerning the internet speakers and buying speakers you haven't heard, people often throw around that everything we hear is perception and only you can decide what sounds good to your ears and so on and so forth but i disagree. if you have enough opinions (which there isn't a shortage of in internet forums) and they all tend to say the same thing, you can assume its a pretty safe bet that you'll perceive more or less the same thing.
audioholics and avsforum (i prefer the crowd over at audioholics) are both really good other forums to check out. also, audiokarma if you're looking for more vintage gear.