Hi there!... the aim of my project is to get 8 temperatures using 8 thermocouples (from 0 C - 1000 C), 8 AD595 for each one to get mV signals from the thermocouples, and then introduce them in a microcontroller to show them in a LCD. I was thinking about using a MUX instead of 8 AD595 (they're expensive) but I don't know which one could work with uV from the thermocouples... =( ... most of them introduce noise...
First read the Application Note for AD 595 and when you get to MULTIPLEXED THERMOCOUPLES it will point you over to here. That provides one way to go about it. When using the AD 595 make sure you pay strict attention to layout!