This can be a fairly simple move, the most downtime I believe would be as your DNS propagates to reflect the new IP, but as you said most of the work can be done ahead of time before that final step to add the domain. As an added note GoDaddy may have a transfer service and might do this for you seeing as you're using a higher level service. I can assist however: I will need access to the host accounts to be able to 1) copy files and 2) copy the database. Since you'll be keeping the same domain name I'm sure, there should be little in the way of updates necessary to the database. Also, take a quick look at my profile/feedback and you'll notice I'm a 100% trusted freelancer, a reputation built from perfect accuracy, attention to detail, excellent efficiency and great communication. I strongly believe I'm the perfect candidate for your job and you can be confident knowing you've hired a professional who delivers on-time. Thank you for reading my proposal and I look forward to hearing back from you toward the start of a healthy working relationship. Kind Regards, Kenny