There are more ways of achieving a Cat A licence than labouring through the full approved full-time course....they all have the same basic requirements of passes in 12 Modules, completion of Practical training and assessments, and a minimum period of relevant work experience, which varies in length from 1 - 2 years according to whether or not you do the full approved course.
Distance learning is one way; but beware of non-Part 147 long-established companies recycling and selling old and out-dated material which will not help you in the exams. You have to take the exams with a Part 147-approved organisations or the CAA (in the UK), and arrange and pay for that yourself. The danger is that although it shouldn't happen, the material you study can differ from the material the exam tests you on.
One Part 147 company (Bostonair Training) has recently launched what they call a Blended course, combining home study (assisted by an on-line course) with weekend sessions for revision and exams run in-house under their own approval. It does not include the Practical, but that can be arranged. (They will also be running exams every three months or so for any/all Cat A and Cat B1.1 Modules, ie you book the exam you need and they'll run it, as I understand it.)
Several companies are now encouraging unlicensed mechanics to get an A Licence, even for Base maintenance work, and one or two are insisting on it as the benefits to the company of this become more evident.