Like this: http://www.thinkscape.com/SharePoint-Online-File-Migration-Tool/
Very good tool with an integrated checking rules on file size, path's and file types that will not be sent over. So you can clean your file system before a full copy.
Just in case you still have windows 2003, Now it is the time to upgrade.
Windows 2008, 2008 R2 and now 2012 are out, so jumping from 2003 to 2012 could men lot’s of extra work if you use Active directory and Exchange 2003.
There are some very good “how to upgrade” blogs/documents out there, but every case is a case, you my get stuck without any useful answers from those main stream “how tos” when you get some strange errors. Best Approach is to upgrade by steps, 2003->2008R2->2012.
Virtualize your Windows 2003 box and use a test environment to test the upgrade.
There are loads of options from Microsoft to Linux (paid and free versions).
But there is something that you need to take in account before you start. When the system brakes (Hardware or Software) how fast do you need to have all back up working?
You can have your system hosted, in this case you only will have the computers or terminals in your premises along with the printers. This my reduce drastically the value for the solutions because you hare hiring a service. You will have a Service Level Agreement that gives you the worst time scenario for down time.
These days you can have even the phones hosted, with hosted solutions you can grow without the problem of physical solution.