Hey Dizzy - it doesn't matter if your CDC lived next door to you - you would still have a different set of clients as most of them come to you through word of mouth (although the website helps).
The training is standard for all new applicants - the older CDCs should all have had a refresher day by now, so he should be doing what the rest of us do!
He will have no objection to sponsoring you (he would get a certain percentage of your orders from the company!) plus it is company policy to encourage clients to become CDCs. If he does get a bit funny, then go direct to head office and they will help you out.
You will need to fill in an application form, with a BMI of 28 or below and at least 2 weeks' experience of CD. If that's successful, then you'll get a brief telephone interview and an invitation to one fof the bi-monthly training days, usually held in Birmingham or Corby (altho I think there were some in Blackpool recently??). The day is free - you pay 75 quid for a business kit at the evaluation stage. CD have lots of financial incentives to help newbie CDCs to get up and running - they're really very helpful and lovely people!
I say, go for it!