I'd enter the competition if the price was nice.
You'd probably have a class for each kind of sensor and store the config in the inbuilt EEPROM (512 bytes).
The tricky bit is storing large amounts of data. Either a flash chip or a SD card would do but I never had any luck with the SD.
How do you usually interface with data loggers? Is sending commands via serial the best idea?
That makes it reasonably easy to dump data and change the configuration.