if you don't already have the Factory Service Manual for your 96, get it before you begin. Also, if you get a different year L67, get that FSM too.
Your cluster should not be a problem unless you get the drivetrain from a 97 or newer. I've done some research and found that the sending units have different output range begining in 97. Also, the fuel level signal goes into the PCM and is outputed to the cluster as a Pulse Width Modulated (PWM) signal. You would have to verify that the 96 PCM sends out the same PWM.
By looking at the diagrams, the shift mode is determined by a 348 ohm resistor for preformance shift and an open circuit for normal. I plan on using a push-in illuminated switch from the Shack or somewhere but you could probably get the switches from the junk yard of from someone here. As a precaution, I'd suggest getting a length of the wire harness in case your car is not equipped with it.
I also noticed that there were several differences in the engine harness connector/grommet from the L67 to the L36 so you might want to get the inside half of that connector as well.