Pick a new teacher

So my son's teacher and I have decided to have him have a trial lesson or two with another teacher, to see if that ends up helping the problems he is having in his lessons.    Thanks for everyones help and advice - it was well appreciated - and I'm going to be reading them over again a couple of times because there was a lot of good info.

So, my son's teacher (who is the head of the suzuki program in our city), has given me 2 teachers names that have room for me to contact.  1 is my son's group teacher, which may be a good choice, except her other job means that we will have to be flexible with scheduling - which I'm not sure is the best situation for my son - but may be offset by him being familiar with her.   I also know that her own son had given her similar problems.

I don't know the other teacher.