Look on ebay. I got mine from a seller named "Jetson" good prices and GM parts. The emblem for the 06-09 Trailblazer SS is the one you want. I have it on my car and it covers up the bowtie holes perfectly. Someone on here also has one on the SLP landing pad for the stock front grill and it looks good.
Heres my trunk
The emblem part number is 15211285 and its like 5 and a quarter inches long.
Check out this link http://www.camaro5.com/forums/showthread.php?t=58490