You can really use any porridge as long as it's not flavoured (a lot of the sachet varieties are), and it does count as a Healthy Extra B.
Brands that I can think of (but not exhaustive) are Quaker Paw Ridge, Oats So Simple (plain), supermarket brands. Alternatively, just buy a bag of porridge oats - no need to buy the more expensive pre-measured sachets.
Quantities - 28g porridge oats + 1 oat/scan bran makes up a Healthy Extra B. The sachets are usually 27g or 28g, so they work as well - just double check with the weights though!
