Thursday 8 September 2011 10.29am
Silverjam - The trains from London Bridge do that in the week but not for arriving early on a Sunday. Cab to Victoria and then Gatwick express is an option and probably quickest/cheapest, but with baggage it is a bit of a faff.
Lagse1 - http://www.expcar.com/
is worth a look/call. They have a base just off Great Dover Street
. Used them for SE1-Heathrow transfers and they were efficient and decent value - £30 I think, although this was a while ago.