I cannot recommend enough Tring Park... they run a BOYS Kickstart programme one a month (term-time)... my son has been attending for the last two years and has found it an invaluable part of his training. Link attached:
http://www.tringpark.com/reach4dance-outreach-and-community/days-of-dance
They are boy only classes, and where possible they try to have male teachers as well.. their day can be spent doing a variety of dance inc Ballet, Jazz, Contemporary, muscial theatre, etc. There is no audition.. you just fill out the forms and send in for each term and at only £15 for the whole day its 'priceless' in my opinion.