eps painting

If I were to seal an eps blank with spackle do I still need to use water based acrylic paint or would some other type be suitable as it won’t come in contact with the foam?

I don’t have a air brush and I want to do a faded stencil design on the deck so I think brushing is out of the question. Are spray cans of water based acrylic paints available? Any suggestions (paint brands)?

Thanks

Bill