Can't you get your sofa in a solid? I'd do that and add more pattern with pillows. A swoop chair like this with a small patterned lumbar pillow could look nice too.

I would go with navy for its the dominant colour in the rug
the others use as accent
http://www.bing.com/images/search?q=navy+sofas&FORM=HDRSC2#view=detail&id=2FE59BFD7C3317750A3A942C1D956E88A5F51023&selectedIndex=108

Really like the rug. I think if you're going with an odd white sofa, navy chairs would be nice, however pet hair, if you have pets, may be too much upkeep. Consider s solid and punching the pieces up with pillow...they are cheaper to change out as the seasons and your taste changes. Also, look at blue grey fabrics against the rug. Stripes would look nice

BTW, check out chairs from Ikea or other companies, that have slip covers. That will give you some variety. Sometimes these companies have denim colored covers and depending on accessories, that might be fun and practical. I've seen dark denims as well as off white denims. Also I think either Ikea or Pottery Barn has chairs with a variety of covers. You can change up the look when you want.

I was going to say stick with plain colour sofas and chairs ie second darkest blue and add plain colour pillows in the other colours from the rug - IMO if you add more pattern you head may start to spin !! ( but that is only my opinion ! And I'm a little bit boring !!! Lol !!)