Use all the parts you mentioned on that 360, they will only help. I would regasket it and throw in a new timing chain/gear set while you're in there, then give the motor a fresh coat of paint. And yes I would run the J heads. The 1980 360 is going to have as big of chambers as ever made anyway so you won't be losing any CR by changing them. Should give you a fun combo to beat on for a few years until you're ready to step it up.