I use a "D" texture dalsoft crepe (11.5 iron) from a cobbler downtown that runs me about $27 and can get a few pairs out of it.
Contact cement can be purchased at any hardware or shoe repair shop. Simple coat both sides, let it dry until tacky to the touch, and press both ends together. To cheat a little, a small bit of hot glue can be jammed in / fur covering the sides.
For those of you who work on many pairs of feet, I highly suggest looking into the material.