Expired domains? Backorders? How to buy?

I am trying to buy expired domains with pagerank for my link exchanges.

Somebody knows where can I buy expired domains? I found backorders.es for spanish domain names but I also need backorders from Germany, France, Italy and USA.

Any website to buy these domains?

Once I have the list of backorder I am using bulk hosted scripts to filter the list and get domain names with backlinks but yahoo its always baned me and I dont know how to filter this list...

Any ideas to get domain names with backlinks?