Suggestions for a good air filter for my room?

[McPhreak]

Hey folks,

Right now I'm living in a room 12'x15'x11' and since it over looks a fairly busy street, there is quite a bit of dust and other stuff which I do not care to breathe. I need some suggestions on names of good hepa filter system (No ionic breeze, please) to use for a room this size as well as where I could get these. Thanks!

 

[db]

one thing to look for is how easy and expensive/cheap it is to change the pre-filter.
sometimes sam's club carrys hepa filters.
if you don't like the ion thing, get one w/o or can be turned off.