So. You want more power, depth and refinement than you currently get with 5" powered hi-fi speakers. You don't want the boxes to be much bigger or heavier. You predominately want to listen in the near field from, more or less, one position. You'd prefer to spend less than $1,000 but could go a bit higher if you were convinced it was the right product for you.
I don't normally recommend a 2.1 system as a first option but in your use case I think it might be the best solution.
Since you are going to have a sub anyway you could save some space and money by getting a pair of good quality 4" mains. You should be able to site a small sub more or less out of the way and still get a decent, smooth low end at your primary listening position. At a push you could sit on it.
So this would be my first choice. EVE SC204 + EVE TS107.
http://www.musictech.net/2014/03/eve-audio-sc204-ts107-review/
http://www.soundonsound.com/sos/mar14/articles/eve-sc204-ts107.htm
http://www.eve-audio.com/index.php?page=SC204
http://www.eve-audio.com/index.php?page=TS107
It's not the cheapest option but it does have several valuable features not found on alternatives. All the units are digitally controlled with built in DSP to provide unrivalled room correction and adjustment. All system parameters, including overall system volume, can be adjusted with the supplied remote control. The mains are tiny and come with excellent mounting options including a back plate for flying them from a bracket or mounting on a stand. you can even use a standard adjustable mic stand via the socket on the bottom.
They really are the best integrated small sub and satellites I have come across. see the reviews. Very smooth. All speakers are to some extent a series of compromises and trade offs. I like the EVE house sound for music. A touch dry in the midrange.
For a bit less you could pair a set of ADAM A3X with an ADAM Sub 7. You lose the most sophisticated controls, including system volume on the remote. The characteristic house sound emphasises a clean and detailed midrange which makes them ideal multimedia monitors because you can always pick up the dialogue.
or there is an even cheaper option. Get the widely recommended, slightly larger JBL LSR305 together with the matching sub.