<p>I need to simulate a low bandwidth, high latency connection to a server in order to emulate the conditions of a VPN at a remote site. The bandwidth and latency should be tweakable so I can discover the best combination in order to run our software package.</p>

In the past, I have used a bridge using the Linux
Netem
(Network Emulation) functionality.  It is highly configurable -- allowing the introduction of delays (the first example is for a WAN), packet loss, corruption, etc.
I'm noting that Netem worked very well for my applications, but I also ended up using
WANem
several times. The provided bootable ISO (and virtual appliance images) made it quite handy.