Just received the "Arkona." No crew provided(as you surmised), but any of the 1/72 U-Boat crew or the Revell Kriegsmarine crewmen (particularly in their foul-weather gear) should work. The "Arkona" really gives you 2 "ships" in one, in that there is a large rescue launch on board, which could serve as an interesting model on its own.
I haven't found any aftermarket accessories specific to the "Arkona," but some generic PE items from WEM or others might prove useful, although the model is already reasonably well-detailed.
The "Hermann Marwede" is a similar, but much larger, rescue vessel which has its own rescue launch on deck (like the "Arkona's"). Not yet available in N. America, the kit appears to be priced between $45-$50 USD by those mailorder shops listing it.
If you selected an appropriate A/C or vessel and figures in 1/72 scale to be rescued you could have a grand diorama with both vessels and their launches deployed at the scene.
Too bad most of the 1/72 ships are WWII vintage or relatively modern small warships.
Maybe A/C are the way to go
. Zepplin?
space capsule?
"Should we prosper it shall be as is our custom...by Miracle"!