Just throwing in my recommendation now the decorating work in my house is complete: Ian Day:
http://www.checkatrade.com/IanDayDecoratorsLimited/
Ian and his team decorated my whole house in Tooting, including a new loft conversion. Ian's a great guy as are his team, kind, courteous and clean up after themselves. They transformed what was a shoddy loft conversion into a great-looking space as well as leaving the rest of the house looking fabulous.
Ian also introduced us to James Webber - a carpenter and builder who has done a great job for us with tiling, built-in furniture, cornices, skirting boards etc.
I would highly recommend Ian for decorating and James for pretty much everything else and they work well together.
Hope that helps!
SFK