Try
www.rockauto.com for a large selection of parts.
Find your year/model of car at their website. It seems the wagon is listed as having the larger diameter caliper. Measure yours and compare with diameters listed at the site next to the part number.
Not sure what area your stating is hanging up. Suggest unbolting the torque plate and brake hose then removing as a unit. Once off you can work on the problem at the bench.
Can you back off on the emergency brake shoe adjuster, remove the rotor then pop out the end of the cable. This cable should run to mid car frame to meet the other side cable at the equalizer, then one cable runs inside of the car. If you need to back off the cable do this at the equalizer.