I'm not sure if we have enough time or how you would choose, but here are a few ideas that you can combine.
Pictures of the popular engines 340, 426, 440 preferable with the fancy dancy intakes, like a 340 6 pack, 426 dual quads, 440 could have a shaker set-up on top?
Pictures of the years gauges, like a 70 R/T, then 71 and up Challenger & Cuda's and also the standard gauges.
OR this could be a good one,
front and back ends of the model years so you would have the front of a 70, 71 & 72-74 Challenger with the rear of a 70-71 & 72-74 Challenger, do the same for the Cuda and group the same.
I know putting something like this together is doable but the time frame may prohibit it. Just my
to add some spice and variety.