Try AFT in Coventry
www.flyaft.com they do only CPL(A) as well as IR, ATPL, CPL(H) groundschool, or at least did when I was there.
From what I remember, the CPL coursework closely follows the ATPL coursework, in the coressponding subjects, if you want to do the IR you need to do another 7 or 8 subjects, that is why most people do the ATPL sylabus.
Give them a shout, now they write the Jeppesen ATPL notes, so must be good.
FB