Indeed the they are the 993's "cup." In 1:24 scale the only kit that I know that has them is from the Italeri Porsche 993 Cabriolet or you can source out a 1:24 Burago Porsche 993.
I like the engine bay, it's very different. Have you seen the 1:1 944 to 968 conversion kit? It gives the 944 more of a smoother look. Probably you can get some ideas from it.