need PC speakers

Hello,
I need some good small speakers for my apartment. I am not looking for the absolute best, but something that can fill the room nicely.

Room specs:

• Plaster walls
• HW floors
• Minimal décor (zero clutter)
• 2nd floor Apt.

PC specs:

• Windows XP
• Creative Sound Blaster Audigy2 ZS sound card

The attached image is the layout of my space and shows where I would like the speakers

are you looking for some "ambient" sound kind of thing? cause that placement isn't that good for that, if you ARE looking for just music to listen to while around the house, we'd need to know some other things, such as:

Budget,
music preferences,
and anything else that could be useful...(are you putting the speakers on the little side piece things, like with wall-mounts?

The main purpose of this setup is to drown out the city noise. My main genres are electronica, trance and some techno.
In the diagram where the green dots are, there is a header beam that comes down from the ceiling about 2ft, and was thinking about mounting the speakers in the corners of this beam and the walls (its like a huge doorway with no door).
I would like to keep everything under $800 usd.

I would like to go with a 2:0 or 2:1 set up so that I don’t have wires everywhere, but I will leave my options open.

Also, is it possible to hook up some type of receiver to my pc and use regular stereo speakers?

Thanks for the replies