I have a dedicated chest freezer that I use as a fermentation chamber, so you can get rather precise control of your temperatures.
I also ferment in SS corny kegs, which personal experience has shown have a surface temp and internal temp that are within a degree of each other, even while fermenting vigorously.
For temp control, I use the ebay temp controller, which has it's own
mega-thread.
As for ramping 3 degrees a day, nothing fancy. I just raise the set point on the temp controller by 3 degrees
