Just wanted to post an update on the suppliers. I am currently on Economy 7 but want to switch to economy 10. It appears that most of the suppliers listed in the document no longer offer installation of a new meter. They are happy to offer you a tariff if you already have a meter though. The only company that I found that is happy to install a new meter free of charge is SSE. Their prices are rather high but there is no exit cost and an assistant I had a chat with to told me I would incur no cost if I wanted to switch providers before the end of the contract. I find it hard to believe so I think I need to do more research but just in case I printed off a copy of my online chat.
I live in London, anyone has been in a similar situation?