@Knarf: Thanks for that, that's extremely helpful. The problem with easy solutions to almost anything these days, from publishing to rock-climbing, is that not only is it possible to do what you want to do much more easily and quickly, it's also very easy to set up a company catering to those needs, so we now have a gazillion companies offering pod services* to choose from. But Lulu seems to be the current go-to small press printer for all the reasons you've stated above.

*Including presumably the optimal size and shape of pod for Body-snatching.

Lulu's print quality is quite good.