Can I remotely access my files on the server though the Internet?
You can remotely access the server though Hamachi ( A VPN available at http://www.hamachi.cc ).
There is a broadband limitation you need to consider though. This limitation effects any solution you might consider for this type of access.
Most broadband/Internet connections are highspeed in only one direction (The download). So you might typically see 3-5MBs downloads, but less then 1Mbs upload speeds. This means that accessing the server remotely will be very slow.
Reading a file from a remote workstation is an upload from your servers point of view, and a download from the workstations point of view. Writing a file is the opposite. Writing the file you are uploading on the workstations broadband, and downloading on the servers broadband. So you have to consider the upload and download broadband speed of BOTH sides of the connection. If your workstations will normally only be reading not writing, then the workstation upload speed isn't critical, but the servers upload is. If the workstations will normally be writing but not reading, then the workstation upload speed is critical, the servers isn't as important.
One way to lessen the impact of this is not to "work" on the server, but instead copy the files off the server to the local workstation, work on them, and then copy the file(s) back to the server.
If you have a broadband connection that has an upload of minimum 1Mbs, but 3Mbs would be better you should be ok (it will be slow, but useable) accessing the data remotely. Anything less than 1Mbs on both upload and download, you should probably do some testing to see how well it is going to work.