I was able to setup a IPSec VPN on a Linode virtual server without too much trouble. They make it easy to add an extra network device as well as a private IP address, so after that, I did the usual /etc/racoon/racoon.conf to match up with a pfSense box on the other side, and voila!
One thing I overlooked was that I only want my single private IP address to be able to connect to my private network, not the entire Linode private IP space! I fixed that, but also need to add more rules to my firewall to make sure that other Linodes are securely blocked from mine.
This is a great thing because I'm now able to easily expand on my main network.