Yes, I'm talking about the already existing vacuum port which exists and is pictured in slide 08.  There are two twin vacuum ports on the subaru intake manifold, one is in use, one is plugged off.  I suggest using the left hand one for your vw brake booster feed (as per kep instructions), and using the right hand one for your vacuum feed needed for the charcoal cannister.  You have the right idea already as you mentioned that you are planning on routing line B to the 1/8" barbed hose fitting on the right hand side which is now plugged.  You're good to go. 
Don't worry about the rest, I got you confused.
 
I just don't know what part you're referring to.  The only thing I know of over on the left side is the fuel injector, and the IAC.  Take a look at slide 08 again and see if you see it there?  
AHA.  Just got off my lazy rear and took a look.  What you are referring to is the  Purge Control Solenoid Valve.  Take a look at slide 01.  You'll see it's location marked although it doesn't have a very good image of the valve itself.  It has two similarly sized vacuum hoses fed off of it and mine is brown plastic and has an electric lead with blue connectors on it. 
One of the vacuum hoses goes towards the front of the motor where it turns into steel tube and ends up as the bottom of the two steel hoses that stick out from the front left corner of the suby engine, near the ps pump.  Because you are simply connecting a small piece of vacuum hose between those two steel tubes (as per slide 01 and slide 04), this lead is a dead-end. 
the other vacuum lead runs up to the top of the throttle body.  This is the one that you will splice into with a tee to feed the purple line A to your charcoal cannister.