But seriously:
Im currently with British Gas for my supply so do I need to contact them or who if not please?
You need to contact the DNO ( Distribution Network Operator ) for your area
http://www.energynetworks.org/info/faqs/electricity-distribution-map.html
British Gas sell you electricity, the DNO bring it to your house
You can't have got a proper quote from them.Western Power and they want a grand + Vat!!! Daylight robbery