I'm pretty handy, but this is a touch past my previous experience. I have a friend who will be helping as well. He's a "handyman-type".... I know this sounds like an accident waiting to happen, but we're pretty thorough and don't leave anything to question.
Good. I don't want to be semi responsible for an accident.
The PID should have the SSR built in or is this a component? As far as I can tell from the PIDs I've been shopping, they seem to be part of the unit...
Its a (slang) terminology thing. Solid State Relays are their own entity, separate from the PID controller. Where you are probably getting confused is that some of these devices have SSR "outputs", meaning you can program them to output a signal that works well with an SSR. The SSR output is what connects to the SSR itself.
Don't worry about all the tech in the wiki page below. All you need to know is what it does. An SSR is a switch that is controlled by an electric signal. In this case the PID generates the electric signal.
http://en.wikipedia.org/wiki/Solid-state_relay