The TC line provides famous Bilstein quality at a lower price.
This set includes all four struts/shocks. Especially on a B3/B4 chassis, if you are still on your original shocks, you will not believe the difference that this inexpensive upgrade makes. Handling is greatly improved of course, but even braking and acceleration become more effective, since your power is being put to the ground, not in all other directions.
If you have just purchased an older Passat, this should be your first real upgrade, after taking care of normal maintenance needs.
Consider also replacing your upper strut bearings and mounts (see recommended items below), and you may wish replace the mounting hardware as recommended by the factory manual.