You may consider taking the trainer you plan on using, if you plan on using one, with you to evaluate the dog. I have done this many times and feel that my opinion on a dog helps the potential adopter make the right decision. Wether from a shelter or rescue, an unbiased opinion of the dog can help avoid the puppy love goggles.
The trainer will know what to ask the fostering home as well.
When a dog saves the life of a man, it becomes clear that partnership knows no bounds.
Fama - T.E.D.D. OEF XI-XII (GSD)(RET... )
Marshall - T.E.D.D. OEF XII-XIII (Lab)(SF EDD)
Lucian - Med Alert (Cane Corso)
Pud - the old man (Pit x Lab)