Armorama Campaign

Almost finished with the turret. And thinking on what to do next. I've found a soon-to-begin campaign on Armorama, and enlisted to it. It begins in September and finishes in next April so seems to be quite enough time to finish a model. My decision was based on my other idea: I'd like to present the German TD line of World of Tanks in the next five-ten-twenty years alongside with other interests (modern Russians, IDF, US, German AFVs, etc.). So I have at least 3 possible models on the shelf: (Dragon) Panzerjäger I. Ausf.B., (Dragon) Marder III M (opened box, and cut some parts but almost intact) or (Tristar) Marder III H.
Or I buy Tamiya's Jagdpanzer IV./L70, my personal favourite in WoT (and most played, most succesful vehicle, as well) and build that. I have time to decide...