Canon EOS, pretty much any of them are good for starting out. the 450D for example.
http://www.warehouseexpress.com/buy-can ... s/p1024467" onclick="window.open(this.href);return false;
The important bit for racing really is to get the right lens, somewhere 70-200 or 300mm is good for starting out. The bigger the glass the better rather than the longer length. If you have decent glass you only lose a little putting a 1.4 or 1.5 adaptor on it to get the longer telephoto, 2 lenses for the price of one and a bit
You don't have to buy a Canon lens, Sigma do some very good lenses for a smaller kind of price but still probably more than you need to pay for the camera body itself.
I use a sigma 70-200 f2.8 , the later version of it can be seen here. It still works with the canon intelligent focus and is a quick to focus lens anyway. (hsm stands for high speed motor)
http://www.warehouseexpress.com/buy-sig ... t/p1027430" onclick="window.open(this.href);return false;
Then you'll be wanting a monopod, these things get heavy after a while
http://www.warehouseexpress.com/buy-man ... ack/p10885" onclick="window.open(this.href);return false;
THEN once you're hooked you'll sell that lot that you just bought on ebay, and get the better stuff later. IF you don't get hooked you haven't spent so much money.