Try these-
Public Liability - Willis
www.willis.comMake sure this covers all aspects of your working environment. Tools, equipment, ladders, damage to properties, general public, hire of equipment if stolen, loss of earnings etc...
Accident & Insurance - Fed of Window Cleaners
www.f-w-c.co.ukif your working on your own you need insurance, especially if you have an accident, god forbid. DONT sell yourself short just to save a few quid because when you need it, you will wish you had more!
Make sure you have the right insurance cover for your vehicle. i.e. for and including business use. If you don't and the police stop you, YOUR IN TROUBLE!! Make sure your cover is inclusive of tools, equipment etc..
Otherwise, have fun, good luck.
Trev