My opinion is that full systems are pretty over the top when a simple slip on changes the sound jsut nicely. I've a cbr6 too a 2003...
Now my underseat jardine slipon has done a treat with the sound of the bike, i could'nt be happier. I bought the exhaust from ebay (i think it was delivered form america) simple. easy.
And this is what i think you should do to dood

PS mine was like 200-300 pounds. (2003).