I am sure other heatsinks are available. However you will need to qualify this solution for your own enviroment.
Is it enough a heatsink without cooler for properly working the board?
How can I measure it?
Or may be there are some recomendation about choosing a heatsink?
What did you decide to use for a heatsink?
I'm also worried that the chip will get too hot if I don't cool it properly.