Well there is a mixed bag of mod info for you.
There are not specific PzEngineer or PzRecon uniforms, they fall under the title of "Mech Troops" along with PzGrenadiers.
The bad news is that in the game the German Infantry and Mech troops share the same bmp numbers (except for the helmets) and so there is no difference between them from 1941 until May of '44.
The Good news is that Andrew TF did an excellent mod for them. You will find them in Green as Jade's CMMODs - link given by the previous responder. However, back in the day, Andrew TF went by the Nom d'Plume of "Astro Cat". So go to GAJ's CMMODs/CMBB/Astro Cat/page 6/HEER-1 to find your mod.
Enjoy,
DavidI