I have a Mac Mini, which has an internal CD drive. I have an external floppy drive for the 2400 that came with it and another USB one (to transfer files from the 2400 to my Mini).
I have the original CD in OS8 that came with the 2400, which always was a mystery to me since it didn't come with an external CD drive. As I recall the OS (called SSW then) was already loaded.
I don't have another Mac (with or without floppy). The Mini is my everyday Mac, which I use with a Cinema Display. Actually I haven't used the 2400 in years... I just charge it up from time to time so it doesn't die, in case I ever want to use it again. It's stayed alive all these years; it's a shame to have to give it up just because my dodo friend decided to mess with it.
The store I took it to said their CD drives were USB and so couldn't communicate with the 2400. The Apple store doesn't deal with older equipment.