Hang on. A high-key image is not a high-contrast image. Blown highlights do not make a photo high-key (it ruins a photo in my opinion, unless it's just the background). You'll need a good lighting setup to do a nice high-key image, but please don't think by just blowing highlights or overexposing an image means you have high-key.
The best explanation, with examples, I've found is here:
9. High Key Imaging
"...high key lighting in the digital age is where...all tones in the image will be above 128 with the exception of a few black tones"