Thickness of copper sheet required for heat sink fins

I'm going to be putting some copper fins on my Aspire One "heatsink" to cool it down (and hopefully kill any need for the fan to be on). I know the dimensions I need, but I'm wondering what thickness would be best. Any suggestions?

 

It depends on so many things, but I would recommend 1mm or so. Don't go too crazy with them.

 

1mm is small and fragile. Good thickness, but if you want some sturdiness, then do 1.5-2mm

 

Thanks guys. A few other questions; does patina matter? I was planning on getting recycled copper since I'm a hippie of sorts, and my guess is that it doesn't, but I wanted to be sure. Also, do either of you have any recommendations as to where to order it from?