Hi Simeon
I have used aliphatic PVA with good results, buy it in bulk and it is not too expensive. Basically the glue is just holding the strips until you get to the glass so anything will do just remember to clean the drips as you go. Bjorn Thomasson uses a no glue technique and relies on the wet out coat of epoxy to stabilise the strips enough to pull your staples. I have used that technique once, it works but I dont have the building skills Bjorn has so I will use the PVA again next time. As for the gaps, fill them later rather than try and do it while glueing, cleaning excess thickened PVA would be a pain, there are lots of filler options when you get to it.
cheers
David