Revamp of website

Hi I have a website that Im wanting more functionality added to.

If Im wanting to update the site's content I need to contact my developer to do it. Im wanting a new site built with the same design but using Joomla or suchlike so that I will be able to update content in my own time. Therefore I would need the front end redeveloped in Joomla?

Secondly I would like the following functions added to the site:
1. A blog which will post to facebook and twitter.
2. The ability to book an appointment for a free site visit.
3. A tool to measure roofspace using a google maps or such like. The tool would allow the customer to measure his own roof. I know that there is a Joomla app which might do this already.
4. Once the roof is measured - a quote will be calculated for the customer and if required sent to his email address, showing the cost of the installation and some other basics - return on investment, energy to be produced by system etc.

I would like a quote for the front end to be developed and:
1. Option 1 only
2. Option 1 and 2
3. Option 1,2 and 3

Ideally Im looking for a developer in Uk, preferably close to London so Im able to have a face to face meeting to discuss the site and any other issues while the site is being developed.

Please let me know if you require any further information.
Regards
Andrew