While prime rib can be sold bone-in or boneless, a bone-in roast is the best bet for guaranteed juicy succulence. A good rule of thumb for purchasing bone-in prime rib is to buy one pound per person.
If you’re buying this cut on the bone you can order the number of ribs you want. A one-rib piece makes a generous meal for two people; a three or four-rib piece (weighing about 2.5kg/5lb 8oz ...
Rib - better even, Prime Rib - works well, as it will be cooked on the bone. Keeping the bone in makes for a tastier piece of beef when cooked but both Sirloin and Fillet are very good.