Hi,
I have used Alan at AAB Electrical for a number of jobs in the past and he is SW4 based. He turns up to assess the job, is very clear about and reasonable with his charges, can often give a quote for the whole job rather than an £x per hour, and is meticulous with the paperwork, electrical safety requirements certifications etc. A lovely guy and tidy. I haven't had need to use him for 2 years now, so hope he is still contactable via the link below:
http://www.aabelectricalandplumbing.co.uk/contact