I recommend you download and burn a minimal CD.
Then Debian will install the critical pieces, and you can download the rest of what you need. I'm not aware of any option to download a k8 kernel right off the bat. I would download the i386 ISO, install it, and then download/build your own k8 kernel after Debian is installed. I just built a new AMD64 machine so I'm about to head off and do that right now.