Hi Tarasque,
If you want to contact me directly I can give you some advice and perhaps help you move everything. I have had very good luck moving sites to a server I have using the following methodology:
1. I make a complete backup of the database using phpmyadmin (note that any posts/comments after this point will be lost).
2. I make a complete copy of the files on the server, and move them to my server.
3. I create a new mysql account on my server and upload all information from the backup in step one.
4. I update the config file to use the new db info.
5. At this point the blog is up and functioning on the new server except that it is at an ip address rather than a domain name.
6. I put a forwarding page on the old server pointing to the new one by ip address so for a few days the blog is really at an ip address but you get taken there automatically from the old site. I take the blog off of the old server at this point so it can only be accessed at the new place.
7. I update my dns information with my domain name host and wait 48-72 hours for everything to switch over.
Downtime: 0
Lost information: only that between the time you make the backup and get running on the new server. Usually almost nothing on all but the busiest blogs. Zero if you either disable posting temporarily or pick a time of day that is dead.
I hope that helps. You can find me via https://htmlfixit.com contact info.
