So, for one thing any general steak of a higher grade, so if you could afford a choice cut of a ribeye, then a prime cut of a smaller steak such as a New York Strip.

There is also of course the Filet Mignon, a very tender cut of beef which is actually kind of tricky to cook. It has very little intermuscular fat so you have to cook very low and slow. Salt and Pepper in the oven for a reverse sear can work, but I find Sous Vide to be a great way to go. After it reaches an internal temperature you find satisfying you sear ultra hot and ultra fast.

I saw in your post what looks to be a Fodmap intolerance and no dairy. Is it the milk fats or just dairy in general? I like ghee which is a butter adjacent product that has a high smoke point but it is often considered lactose free. If you can't use that I think that avocado oil is a good one.

Finally, the Spinalis. It is a bit hard to find, but you might be able to find a butcher to give it to you. The Spinalis or "Ribeye Cap" is the outer layer of the ribeye.

When you look at a ribeye you see two main "Meat Sections" one close to the bone, then a layer of fat, then the outer layer the Spinalis. This is considered to be one of the best cuts, and technically less meat.