It seems to have gone a lot smoother than I was expecting.
Mounted the NTFS drives using fstab by UUID and so far so good.
I think I just need to setup the Crashplan backup software and some nightly backup scripts to replicate what I had setup on the Windows server.
My biggest worry was the WAMP to LAMP move. Mainly the MySQL database. That was really easy. Did a mysqldump on the Windows server and imported that on the ubuntu machine and it worked straight away. Changed IP address on the devices using the database and back up and running.