Little to add to this as I haven’t really used my anchor in anger yet, but I do carry a setup for safety’s sake.
I have a 3kg Manson Supreme which lives in a bucket along with 5m of 8mm chain. In my MkI this bucket sits forward of the floorboards and is nice and out of the way, just beside the mast. I’ve tried dragging this anchor through wet sand and so long as the pull is horizontal you cannot shift it- quite impressive.
My warp is a 50m length of 10mm nylon 3-strand, which lives flaked into a second bucket. This gets used as a towing warp as well. It will pay out perfectly but I envy those who use a mast-pin drum, as flaking it back into the bucket is a pain.