I started last fall with an Allen Bradley Micro 830 system I purchased off of EBAY. The free Workbench has a modern Windows Visual Studio type interface and includes Structured Text, Ladder, and Function Block Diagram logic editors. Depending on your background, structured text has been compared to Pascal and may be a good fit. It has a PID library function with auto tuning capabilities.
My 830 has three expansion slots and it came with a 2080-IF2 . I purchased two 2080sc-IF4U 4 Channel Universal Analog Input Modules that interface directly to Thermocouple or RTD inputs. Onboard it has 14 discrete inputs and 10 outputs.
I don't know if it's a good fit for you but it has a good brewing automation fit for small to medium systems .