As stated you don't need hi temp paint.
Clean them REAL well, ensure that ALL traces of oil/grease are removed.
Scuff with a scotch brite.
Clean REAL well with a prep solvent.
Use an adhesion promoter base coat.
I painted mine with a paint called fast black a few months back along witht the engine took about 2.5 cans to cover nicely, goes on thin and leaves a nice matt finish, I'll post some pics after I finish the rebuild.
I just dyed my covers (2001 600M dark) satin black. Yes dyed them. VHT sells a vinyl dye that soaks into plastic and wont ever chip off. I was skeptical but ordered a can from Summit Racing on eBay. (Arrived in a day...fast.) Two light coats and the covers look beautiful! A couple areas near the bosses and edges pooled a little after spraying but within 30 min it all was absorbed and the finish is completely uniform. Highly recommend it. I just washed the covers in in advance in dish detergent to get rid of any oil and dried them. They have a number of colors including gloss and satin black. I researched a number of other company's products and while they claim use on plastic or vinyl, they are all paint. This is the only spray dye I could find. I can post pics later if you wish.
took belt covers off, washed them with dish washing detergent, then some brake cleaner, a little rubbing with brillo pads, some more brake cleaner, 5 minutes in the oven at 250*f...took them out and sprayed two hands of paint then to the oven again for 5 more minutes and then resprayed one more hand, let dry and then one last hand to even out....