This is something I found recently, could make a decent lowtier German tank destroyer. Most people know the Marder III Ausf.M vehicle - it was built on the 38(t) Ausf.M chassis, which was modified by moving the engine to the middle, giving the vehicle its distinctive look (with the superstructure moved in the back). It's sad that Ausf.M will most likely not appear in World of Tanks, at least not in the 2nd German branch - I can speculate the reason for that is that the Marder III Ausf.H was equipped historically with both the Pak 36(r) and Pak 40 guns (like the Marder II was), while Ausf.M only carried the Pak 40/3.
Either way, in 1944 there was an attempt to modify the Ausf.M chassis into yet another universal Waffenträger. It started as a Mörserträger (mortar carrier), but gradually more guns were envisaged.
As you can see, the defining difference is the very steep sloped frontal armor (67 degrees in fact) - more parameters (such as the armor thickness) are unknown. It was projected to be equipped with various guns: 50mm, 73mm, 81mm, 100mm and finally 210mm mortars (in its "mortar carrier" variant), but also with 75mm and 100mm low-pressure guns, 75mm PaK and finally, 75mm, 105mm and even 150mm howitzers.
In the end, the project was rejected. Only one mockup was ever made in 1944 and after that, the Germans (who preferred the Waffenträger designs based on 38(d) platform, seeing - correctly - the original 38(t) as insufficient) lost interest and the project was scrapped.