Mike,
What is your sample rate going to be?
This device is a good way to log to a SD card. It has several types of inputs. I have used it successfully for several years now to monitor water levels in a sump pump pit.
https://www.sparkfun.com/products/10216
This is a nice processor board that I use in the same system.
https://www.olimex.com/Products/PIC/.../PIC-MAXI-WEB/
Sounds like a fun project.
-Hugh