A bit late to the discussion...
I find tinyproxy easier to set up and lighter than squid, especially for a server that is for only your own use.
The key is whether your datacentre server is running sshd.
If it is, then the answers here that use ssh to do port forwarding solve the authorization issue automatically. Set tinyproxy to bind to 127.0.0.1 and only users which have ssh access can connect to it.
If it is not, then you can configure tinyproxy to accept only connections from certain hosts or IP addresses. If you have a static IP address at home, problem solved.
If you have a dynamic address, you may be willing to accept connections from a sub-part of your home connection. E.g. your ISP sets your home connection to look like 192-192-192-192-area1-san-fran-cal-usa, you could set tinyproxy to accept connections only from area1-san-fran-cal-usa (thereby ignoring the IP part of the connection). The risk is that other area1 subscribers discover your proxy and start using it.
This is what I use for my VPS proxy and it works fine, especially since I am in a relatively small catchment area of my ISP. I've never had anyone else use the proxy, but I know it is a risk (one I'm willing to take -- I can always change tinyproxy if I discover someone else using it).