By using epoxy you insure that your wet out coat of epoxy will have a good surface to bond to. epoxy to epoxy. Wood sealers may not bond well with epoxy. I would not suggest using anything other than epoxy.

Your seal coat will have to cure enough to allow the glass to slide smoothly over the surface of the hull otherwise you will not be able to lay out you glass. I usually seal coat at night and then glass in the morning, up to 12 hrs later. In colder conditions I have waited 20 hours. However I do visit my boat in the middle of the night to check several times. Epoxy is not very good at keeping my schedule. I glass just as soon as I can place the glass on without it sticking to the boat.