I usually try to stay within the same manufacturer when it comes to primer and paint.  I usually go with a high-build primer, but I'm not seeing many one part options for Interlux. 

If you go with Pre-Kote and just dump the whole can of Part B into the can of Part A, there's no way you can mess it up.  You can paint one coat in the morning and one coat that night.

there is a one coat primer https://www.clcboats.com/shop/products/boat-building-supplies-epoxy-fiberglass-plywood/interlux-pre-kote-marine-primer.html that can be used with the brightsides.

my personal recommendation is to skip the primer.  the brightside poly paint bonds very well with the sanded epoxy and the primer tends to make the finish more fragile.   the key thing is to invest in a good sanding so that you have a smooth surface and the paint without primer will be just fine.

h

   Thank you for your sugestions.  I ordered the 2-part Pre-Kote, but will maybe cancel and go without in order to get this thing out of the backyard and into the water!