Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
1) What is a "daisy-chainable" ADC? If you're using SPI, all the devices can share the bus, with discrete select lines.
2) Look at Microchip MC3008. It's about $2 in single pieces.
You asked for an SPI device and then show a non-SPI implementation. As I suggested, using an SPI device would accomplish pretty much what you're showing.