I've tried several different paints over Monokote over the years and the one that stands out best above all the rest is Top Flite Lustrekote. It is available in a very broad range of colors both gloss and matte. It dries very hard and is the most fuel proof stuff I've ever used. It's at least as good in that department as any of the automotive clear coats.
As with all things it's not perfect (no pun intended), because the spray cans that it comes in can be very problematic, especially in cool weather. The cans need to be shaken until you think your arms will fall of then shaken some more. If not very well shaken (and I mean this) the spray nozzle will spatter paint in blobs in all directions.
All things considered, if one doesn't get lazy and really shakes the cans for about 5 or six minutes in temperatures of 72 degrees or higher, this paint will produce excellent results on monokote or Ultra cote. I do wipe the surface to be sprayed with Isopropal Alcohol and buff it lightly with scotch brite, after masking, then wipe with alcohol again just before spraying. I've done this dozens of times with different colors and never had any cracking or peeling of the paint.
As a great bonus the colors will match Monokote perfectly.
PS: Trying to use dope of any brand is a big mistake...don't ask how I know.

Randy Cuberly