I have ForteIIs as mains and have an academy center with two KG1.5s as surrounds. Also helps that I have a SVS subwoofer.
I agree with fletch, the KG line matches pretty well with the Forte speakers. But, if you can afford an Academy it's an awesome center channel speaker. Otherwise KG. Sure, more Forte as surrounds sounds good; but few rooms can accomodate; if so KGs