The small 4" roller like a honeycomb,nylonn/ plastic feel to it, used for textured coating about £2.50 or £4 for tray and roller, need a couple of cheap 1" or 2" brushes too.
You need to make sure the base you are covering is clean and free from any loose bits. Mine was like new after lifting the ply up. You will need something to give the 1st coat a Key to adere to. Heavy scourer or very fine sandpaper, then wipe away any dust.
Hope this helps
Wayne