you might as well go with the first one then, the 4 inch pro with the carbon filter and ducting as a package...
or like buddy mentioned, get a 6 inch inline and keep it on low.
the 4 inch is more than adequate for the 2x2 and you can also run it slower, too. my 4 inch in a 4x4 never goes past speed setting 5....
but really, if you aren't worried about the smell, don't purchase a carbon filter. just save that money