Help me pick an ethically-manufactured laptop.

a noble idea, but extremely unlikely. The coltan in capacitors alone would disqualify almost all devices.

Here is a handy list to make the lesser-of-many-evils choice though

http://www.ethicalconsumer.org/buyersguides/computing/laptop...

A similar question on Quora has not been answered either. http://www.quora.com/Where-can-I-find-information-about-the-...

I have also been wondering if any such thing exists?

From the metafilter comments, and what's been posted here so far, I think the best option is to try to make do with what one has, getting it fixed/upgraded as needed and possible.