Any specialist Engine paint would do the job. I would recommend that you buy from a known brand or supplier. I used Halfords engine paint which is a well known motorist shop in the UK. Because the covers don't get too hot you can use a self curing engine paint on them. Some of the VHT enamels need oven curing so unless you have an oven in your garage. Or a very understanding wife then avoid. Although I understand that oven cured is a very durable finish.
I also used A very high temperature exhaust paint on the header pipes and exhaust which remained very powdery to the touch but once I had run the bike for while they cured great and have a dark grey look to them.
