Opto-coupler is the first step but you really need to get someone else to do the design of your output stage, someone that understands the design problems of ground bounce, flyback and capacitive coupling across the MOSFET. Not to mention cable and connector ratings.
Forget IGBTs at such a low voltage. I suggest something like an IRFP2907.
If this is for regulating a slow changing temperature then SCR/triac could be used, in this case you would also want to employ "zero-crossing".
Evan