Isn't there also the problem that whilst terriers can be lovely, faithful dogs around children, they can sometimes be a different matter if they meet up with another dog?
If someone's prepared to put in some grooming time, cockers are lovely dogs.
Then, of course, you could think about an ex-racing greyhound. They are gentle and quiet, don't pull on the lead, and are very low maintenance. Of course, they're apt to be a little dim, but you can forgive them that. And there are hundreds in need of homes because many people think they're a difficult breed, when in fact, they're one of the easiest.
Have a look here:
http://www.dogstrust.org.uk/rehoming/choosing_ a_dog/
There's a useful factsheet on the breed, which you'll have to register to see.