I don't believe that you can completely remove Tiger. Personally, I have never tried this so I do not know. I am sure someone else will chime in with an answer to this question.
However, you can make a minimalist Tiger install, then use the rest of your HD space for your bootcamp partition. And of course have the Mac by default boot into your bootcamp partition.
To use bootcamp, you will need to set your system clock back. Apple has the tech ref on their site, but I believe anytime before October 1st, 2007.