Don't spray either of those clearcoats over enamel or you'll want to do this:
! You can use Duplicolor's clear over Plasti-Kote paint but I would recommend Plasti-Kote's clear rather than Duplicolor's unless you use the clear that comes with the Mirage set of paints. Plasti-Kote polishes out really well but it takes some effort. Hope this helps! Tamiya gives a good hard clear also.