Pwhyles,
In my opinion, based on your posts I've seen in these forums, you probably won't learn that much on a course for either of those qualifications. Your A Level will have given you a good grounding in the fundamentals that never go out of date. Yes, technology moves on at a pace, but logic is .... well, logic! lol
I'd recommend an ONC or HNC or Degree, you can do all these part time. ECDL and CLAiT are more for the user and office worker. If I remember correctly ECDL was introduced by the British Computer Society to provide a mechanism for the average Joe or Joanne to become acquainted with basic computer skills.
You're way above that in my opinion.