3.50 kg Pale Malt, Maris Otter
0.50 kg Barley, Flaked
0.30 kg Amber Malt
0.30 kg Chocolate Malt
0.25 kg Carafa III
0.25 kg Roasted Barley
41.00 gm Cascade
but haven't got any Carafa III, are there any suitable replacements.
Or is it a crucial element that make the 4 shades stout such a hit?

I don't really want to have to pay for postage just to buy 1kg of grain

I've got black malt and caramalt, would either of those do?