Supported tours with kids: company recommendations?

[stiber]

I posted this on the "Youth Cycling" forum, but it apparently has too low of an activity level to generate a response. I'm looking for recommendations for companies that run supported tours that can accommodate children. In particular, I'm looking for companies that can provide bikes with small frames to fit older, but still less than 5-foot-tall, children and that would have tandems for, say, ten-year-olds to ride with an adult.

Thanks in advance!