We used those OMRON controllers at work on 11 ovens they can be set to be accurate to .5 degrees F or C. Input voltage 100 to 240 AC. Circuit board relay is rated 1 amp you need to use the controller to turn on/off a larger relay for more amps or connect it directly to the on/off switch of something like an oven control circuit. Controller has many options, ramping, memory, etc. You can set ramping to anything you like and the controller learns and remember each time it comes on. Our ovens ran at 680 degrees F controller will turn on the oven and thermocouple tells the controller unit how fast it is heating up. If there is too much wasted power trying to heat the oven too fast change ramping circuit to a lower number then test it. If thermocouple is 30 feet away from the controller it does not have to be a 1 piece wire all 30 ft you can have 3 ft of therocouple wire in the oven and 27 ft of copper wire from therocouple to the controller unit. Experiment with the controller to learn how settings change what it does. Buttons on front of controller changes through a ranges of all the options. Decide what your ON/OFF temperature needs to be, if max temp is 500 degrees and you want it to never get cooler than 494 degrees set temperature differential to 6 degrees then set your temperature to 497 degrees the controller will cycle on/off 3 degrees both sides of 497 degrees. Temperature differential can be anything from 20% to about .5%. If i knew more about what your doing and what you need I can tell you exactly how to set it. Don't put therocouple too close to heating elements it will read temperature of the heater elements and not the temperature of the whole oven. You can do it, it is common sense stuff.
No need to pay lots of money for a factory made thermocouples, make your own. Strip 1/2 inch of insulation from 1 end of thermocouple wire then twist wires together, clamp a stake on terminal onto the twisted wire end. Cut thermocouple wire the length you need then connect it to the Omorn controller. If thermocouple is a long way from Omron controller use copper wire to connected them. I use to put EYE terminals on the end of thermocouple wires so I could bold the terminal in place if it gets bumped it stays in the correct place inside the oven.