I appreciate this is a 3-day-old comment now, but consider MISTer - https://github.com/MiSTer-devel/Main_MiSTer/wiki - which allow access to all of these older systems rather than being locked down to one of them. You could then also move through time, from an original Apple I, through Commodore 64, Amiga, etc. Also permitting your child to learn about FPGA, hardware, etc. at any point.