For me, the bigger and thicker the oats, the better. I had trouble finding anything bigger than porridge oats in ASDA, Sainsburys or Tesco. Finally found them in a local independent market - called "jumbo oats".

It sounds as though these are the exact opposite of steel cut oats?? If so, how are steel cut oats different from 'quick oats'?
On a side note, even the jumbo ones I found seem a little too fine and flimsy to me and it's still a bit too easy to over-cook them. The absolute best I've tasted are those that I found on a visit to Germany, from a company called Al-Natura. The 'Gross Blatt' oats have a lot more thickness and texture than anything I've found in the UK, or back in the US for that matter.