These are all Plastic Soldier Company 15mm vehicles.
First, here are some Marder self-propelled anti-tank guns defending a bridge;
Next, here are some SdKfz 251 halftrack variants;
There are 2 x 251⁄22 75mm anti-tank guns, 2 x 251⁄9 Stummels with the L24 short 75mm gun and 1 x 251⁄16 Flammpanzerwagen.
The 75mm anti-tank ones are conversions using spare guns from the Marder kits.
Finally, here are enough SdKfz 251/1s for two platoons of Panzergrenadiers and two SdKfz/10 command vehicles;
And here are the actual Panzergrenadiers;