private student exchange Germany / UK or USA

We would like to host an English speaking boy during school vacation in exchange with Elias, 13 years old, who would like to spend 2 to 4 weeks with a family in UK or USA to improve his English. We live in a major city in southern Germany, Elias attends 8th grade of a German high school. We do a lot of sports, we are open minded and culturally interested and we already have made positive experiences with a mutual exchange of students, both as a host family and being a guest.
As a teacher I can spend time during school vacations to enable excursions, sporting activities, sightseeing etc.
I hope to find a caring host family for my son - preferably in UK or USA - willing to support his English speaking efforts and enjoying to offer insights into the land and the people.

We would be pleased to receive a response.
Marion