I agree with Markd.
Have a look at something like
the Yamaha Digital Sound Projectors.
My cousin has one in his living room (He also has a main theatre elsewhere in the house) and is pretty happy with it.
You set it up using a microphone so you can optimise performance for a particular listening location by running the auto-setup with the microphone at your preferred listening position.
Paul
The sound bars are not going to offer convincing surround in this case, though, as they require side walls to effectively (debatable) mimic surround sound.
As for the "transparent speaker recommendation, well, that's more difficult to define. I personally believe that no other company comes near as close to the ultimate bang for your buck than Toetm Acoustic but there are many, many other options. B&W, Tannoy, Revel, PMC, some Thiel models, Triad, Totem Acoustic, Meridian and others represent higher dollar options. Mid level options would include PSB, Totem Acoustic, Def.Tech, NHT, Atlantic Technologies, etc. Brands that will never be accused of absolute faithfulness include Klipsch, Infinity, Bose and Sony. All of these suggestions are, of course, subjective and there will be those who disagree with me.
As for the suggestion of corner loading the sub...rubbish. A suggestion to sacrifice accuracy in favor of output is absolutely contrary to the OP's quandry.