Transferring domain to BT, managing the website and emails and probable cost?

[JOC]

It has been pointed out to me that as my business runs on its internet links that I might be on a more secure footing if I have my domain by my ISP (BT).  Currently the domain and emails are hosted by a third party who are not an ISP.

I currently access the internet via a BT Business Broadband connection and pay the going business rate for this. 

I have a .com domain and related emails with the 3rd party domain host.

From what I read it isn't too difficult to transfer the domain to BT - I have just been sorting out mail relay and it sounds easier than that process.  However, will have to re-upload the website to BT's ftp account - this is the bit I am wary of.  My website is vital, but is home produced using Artisteer <50MB - it does all I need it to, but how do I know that it will work on BT.  I upload it to my current domain provider via ftp and it works fine does it follow that I can repeat the process to upload to the BT server without any issues?  Also, will I lose my Google ranking in the transfer process?

Also will it cost me any more than I am currently paying to BT for the business broadband service to make these changes?  NB.  I have read about a one off charge of about £23.50 to shift the domain and this is OK - I'm thinking more of the monthly/Annual charges.

Many thanks

[markp]

Hi JOC,

To transfer a domain name in is quite staright forward.  With your broadband account we give you 10 email licenses which you can use to create domain email addresses, these email addresses are pop only addresses and have a fixed mailbox size of 1Gb.

As for hosting your website, this will all depend on the site itself you might get away with just having our basic hosting pack which starts at £6 a month if you go to BT Web Hosting this has the prices of the different hosting packs. With all hosting you can upload via ftp.

Markp