It's all about What Burns. Don Cab 2 rocks out too. American Don gets too repetitive and too boring at times.
As khchris once stated, Storm & Stress > American Don.
As for Volta Do Mar, they only released an EP and a full-length. All can be found, including splits/unreleased material, on '03 > 98'... which came out last year. They have since disbanded, the guitarist however, has a new project out called 'Oso'. Along the vein of Volta Do Mar, but more folk sounding... ish.
Weights and Measures and Volta Do Mar are nothing alike. Both good material, nonetheless. Jeremy Gara, drummer for Weights and Measures, is now playing drums for the Arcade Fire... pity. Just like Volta Do Mar, they only released an EP and a full-length... all which can be found on 'Invest in the Death of Weights..." which includes all their material, plus some unreleased tracks.
Don Cab - What Burns
http://www.southern.com/southern/band/DONCA/disc.html
Volta Do Mar - 03 > 98
http://www.team-av.com/index2.html
www.voltadomar.com
Weights & Measures - Invest in the Death of...
http://www.escapegoatrecords.com/weights.htm
Oso - S/T
http://www.team-av.com/index2.html
If you enjoy that stuff, I would also recommend you listen to Piglet. Good shit, check it out.