depends were they're goin
There is no exact age. Though Jonas Brothers quoted that they would date a fan.
yes
Nick Jonas from the Jonas Brothers says that you need to be at least 14-16 to date him. He is 15. turning 16 in september.
pajamas?
Yes they do
If you can get to them, and if they are single, you can probably date one of them.
Size 8
Yes they do.
LA
yes
Wayfarers
The ones that the Jonas brothers wear.