Here is a sampling of Pelican for this #threetunetuesday by 
Here is Lathe Biosas that features their unique post rock sound nicely. Its almost like three songs wrapped into one.
They can get quite heavy too. I saw them live with Russian circles what a pairing that was.
Most of their songs are nice for concentrating on working and they take you on a journey with their meandering riffs.
That's all for now, thanks for looking :-)