Loads of good advice available on
ACE worth emailing them for details about your options and considerations when converting a car to a different specification.
(Be aware ACE are having email issues due to spam at the minute )Remember its more difficult to get DVLA to change details on your log book, so worth checking what they need to have from you before you start your project
True the DVLA needs to be informed of all changes to the car, along with your insurance company, but be aware you will get flagged almost certainly for a BIVA, due tot he possible changes that will push it past the 8 point score system the DVLA use.