I do not know the colors but to always have the lockup in 2,3 & OD, connect pin A to switched ignition power and pin B to ground.
So at least one of your three wires will hot when the ignition is on and the other two will be ground wires. The hot wire supply has to be run through a brake pedal activated switch (another switch that you will have to provide). You will have to wire in a normally closed switch that opens when you put your foot on the brake pedal and is activated at the same time as the brake light, so you will have to figure out how to install that part such that it doesn't interfere with the brake light but still work with it.
So A & B are for the torque converter lock up and are one continuous circuit. The other Wire D is connected to an engine vacuum switch that is normally opened but closes when vacuum falls below 8-10 inches of vacuum (provided you don't have a long duration cam). This is a passing gear type of thing that will disconnect the lock-up feature when the throttle is wide open.
As to how much to cut or add to your drive shaft that will depend upon the difference in the length between the two transmissions. Normally a 700R4 is longer than a PowerGlide but you mentioned you have a nine inch tail shaft and most information you read is for the standard (or more popular) six inch tail shaft. So if your PowerGlide is longer than the 700R4 with a six inch tail shaft, then you will have to have a custom drive shaft made unless it is within a half inch or so (I would not attempt to add a piece to the existing shaft).
For shift linkage you will have to make that yourself if you do not buy the available kits. It is a matter of looking at the existing PG linkage and figuring out the gear positions and fabricating a new comb with two additional detent positions.