What I need now is an inventory of all the interfaces that my potential sensors would require. I took the list from the previous log and put it in a spreadsheet. Then I went through each datasheet and looked at the interfaces.

Here are the results if I were to put in every sensor:

From this I can now do a quick look to see what interfaces I need to augment for the Arduino style inputs. The Arduino A/D system does not have the accuracy or range this project needs so an outboard chip will be required. From the above I can see an 8 input multiplexed IC with an I2C interface would be a good choice. For example I will look further into the $2 TI ADC128D818.