Best interconnect cable to pair with my maggies.

I am wanting to upgrade my audio interconnects from my cd player (Marantz SA8001) to my preamp (Onkyo Integra DTR 7.2)and then from the preamp to my amplifier (McIntosh mc352).
I am using magnepan 1.6qr's. I have been looking at the audioquest line of either the king cobras or the columbias.
Would like some advice as to either of these products or something else within the price range of $400 for both new or used. Currently using audioquest copper heads.

See Morrow Audio who advertises here.
Check out the KCI Silkworms... If you can get by with 0.5 meter cables, they will be in your price range. Great pure gold tonality, deep bass, and good soundstaging. You can read all about them in other threads. They come with a 30 day money back guarantee, so you've got little to lose in trying them!

The Jade Audio Vermeils are excellent as well. Again, if you can get by with shorter cables, they will also be in your price range. Jade cables project a holographic soundstage which can be intoxicating. The Vermeils' only significant weakness is that they can sound a smidgen silvery, which can be a problem in some systems. Still, the soundstaging is so great they deserve a listen. Jade also provides a 30 day guarantee.