You should seriously consider to use diskless clients. If you want to maintain a server and 10 seperate client installations it's much more work than just to maintain a server and a client or only a server - I'll explain how this could be possible. Also harddisks are the parts which have the shortest life time.

A reason for not using diskless clients could be the need to work with huge files (several gigabytes) on the clients. For example if 10 people try to edit video files at the same time, your network can't be fast enough. In that case it would be better every one has it's own hard disk to store the own files. Also if the 10 clients need to be very different one to each other, you can't use the solutions I want to suggest.

LTSP is one way to set up such a network of diskless clients. The big advantage is: you need a powerful server (with a lot of RAM) but you can use really old client machines and everything will run fine. Only the client's network cards need to support booting from network (you can buy some PCI networking cards). The user's programms will actually run on the server. When a user runs Firefox, it is actually a process in the server's system. Also the user accounts are users in the server's system, so you won't need LDAP. You'll have to maintain only the server, the thin client is so thin that it doesn't need updates usually.

A good way to run VirutualBox there might be to run it in headless mode. This means windows is always started and running and the users can connect via RDP to it. Note that only one user will be able to use it per time unless you create a VirtualBox machine for every user.

Note that this is a great and very low-maintance system, but you shouldn't expect that everything can be set up from GUI as you request. But I think there are a lot of good instructions out there.

There are also other ways to run diskless clients (if you want the programms to run at client side), but I'm not familar with them.

A last comment: I suppose you can install MySQL at any time, there is no need of any specific order. I suppose you don't want the MySQL users to be managed by LDAP?