I can't give you a clear advise since I don't know the exact design of your notebook.
Can you please make a photo of the bottom side of your notebook with the service door opened?
Then it would be possible to see, where the fans of a cooler-pad should be situated.
Please have a look at my notebook, to see what I mean:
http://www.amilo-forum.de/download.php?id=3035
There are a lot of cooler-pads on the market. Sometimes it is a bit difficult to find a suitable cooler-pad for a 17"-notebook, but it should be possible.