Chromel-Alumel thermocouples come in handy when you need temperature monitoring and control above 200 degrees Celsius - up and not too far beyond thermistors do the job ok in my experience. You can pick up them up for a few <local currency units> but building your own is quite straightforward so why not give it a go? It never ceases to amaze me how many component parts in the most intricate machinery can be broken down to simple components and engineering apart - which can make things difficult for the average diyer like myself - are most of times doable.
Try ebay.