Cf and sd card in d300s?

I'm planning on setting up my nikon d300s with raw+jpg basic. My idea would be to have both cf and sd cards in the camera at the same time and save the raw file to the cf card and the jpg to a eye-fi sd card. This way i can have my laptop open and see the jpg pics right away on my laptop as i take the pics and have the raw copied to the cf card for later downloading. I would delete the jpg and only keep the raws. The jpgs is just so that i can preview the images right away on my laptop screen. Does anyone see a problem with this setup? Would the buffer clear slower in my camera cause it has to write 2 images to 2 different cards?

Try it and find out.

I'm not familiar with the memory card setup of the D300s but I'm pretty sure the manual can verify if what you want to do is possible.

In a programmer's point of view, the easiest way to set up the camera is to save everything to one card at a time only but some savvy computer buff may have thought of it before you did and encoded what you want specifically. Who knows? The manual. Of course.