You have two decent solutions that I can see. You can fire up VNC on the remote server, and grab hold of the console from where you are. This works great, but leaves a potential problem open. If the server crashes, goes to single-user mode, etc., the network services are down, and VNC doesn't work.
There are KVM switches out there that are LAN attachable. I'd get one of those, and plug it into your remote server, and into your network. Get a matching one for your end, and you get full console access, including BIOS prompts during boot time. Plus, this wouldn't interfere with the physical console at the remote site, since they would still have a real console there, if it's needed.
Avocent and Belkin make pretty good products, but I'm sure there are lots of others.