Is there any way to scrape the content of a remote file so that the remote server see's the ip of the user who is visiting my page, rather than my web server ip?

Yes, it's called proxying.
A "proxy" is a program (or server) that sits between the destination server and the user computer, and relay the informations between the 2.

I actually need it to use the visitors IP rather than 1 static proxy IP. Thanks though.

There is a header that you can add to the request for the target server, that indicates that you are a proxy.
Otherwise, the process is called "ip spoofing", and no way you can do that in PHP.
You must alter the tcp-ip packets that go out of the pc to change the origin.
But it means that the server will not reply to you, bu to the ip that's in the origin field of the packet. Making you blind and deaf, speaking to a server, but without seeing any answer.