You'd think Screwfix would have a decent selection of screws, given their name, but they are useless for black screws - and stainless steel screws for that matter. The eBay suppliers are pretty good, I've found. Black socket screws alway look the business IMO, although you can always apply some black paint to a chrome screw. What kind of foam have you got, Owen? Generally speaking, if you blow into it and can feel your breath, slightly delayed, coming out of the other side, it should work. Ot