Kappa 's Biamping

Hi, I wish to biamp my kappa 9's horizontaly with a Hafler dh200 driving the top and a QSC rmx-850 driving the demanding bottom half.
I will be using a Foreplay preamp ( moded with second set of outputs) and Denon cd player has any one tryed horizontal biamping speakers ? Any advice is welcome, I already have these amps and have big eyes for an Aragon or Mccormack in the future.
Thank you,
Guycom