Old new guy...

[Sleykin]

I built mine in 2011 using a JLD612 PID and an SSR. I bought them on eBay as kits go for about $20. This forum is where I got a lot of information from.
Lightobject.com Support Forum - Search
The kits generally come with a K thermocouple that only goes up to 400C* so you need a different TC for higher temps.
Not sure why they want so much more for the JLD612 than the REX C100 but both of them are about the same functionally.
http://mythopoeic.org/misc-files/JLD612_Manual.pdf
Hope this is helpful. I think you will need a separate timer for shutting the system down. The JLD612 will allow you to set ramp up times or temperature stages, but I didn't mess with that.
This is the other manual..
https://www.rkcinst.co.jp/english/pd.../imnzc22e1.pdf