Pupuce
Have followed the discussion with interest, particularly with regard to identifying potential clients.
Have you thought of contacting your local Business Link or Enterprise branch (library or council will be able to put you in touch).
I come from a pr and marketing background and it sounds like you could use a bit of help in this area - the organisations mentioned run free or v.cheap courses (usually 1 day) for business start-up issues, and have access to all sorts of information that would be useful.
Perhaps it would be best to contact other doulas and/or their training organisations to build up a profile of the 'typical' client and how best to reach them in terms of advertising and publicity.
I think it's important to remember that 'benefit mums' (have been one myself on and off for 10 years) do only receive enough money to live off, nothing more. A parent with two children currently receives £108/week - that's food, bills, clothing, everything. Of course maybe the baby's father could/would pay if she asked, or her parents, so don't ignore this group entirely.
I would also recommend that you read Lynne Franks' 'The Seed Handbook', an ethical, values-led and feminine business start-up guide.
Can't help with the name I'm afraid...my hot favourite so far is Scummy's 'Go Doulally' - that would be really memorable and would get you lots of publicity!
hth, love Mopsy x