Hello felix,
first of all, is this addressed for a motorcycle? because 2C2S... I wonder what bike that is!
Anyway, for temperature you will definitely choose a termocouple. Try a J or K type. K goes up to 900-1000 degrees, J will be more precise though for your application.
As for the PIC... well, get something that has more than you need, as PIC are not that expensive. 16F family is more than enough for your application. So, 16F1939 is OK. It largely depends on the screen that you will use, rather than the sensors.