Aaron, the meat removed that results in a rib-eye, is called deckel or rib-cap meat in the industry, It's prized for its flavour and scarcity, - the cut butchers often take home for themselves where i live so its never seen in retail markets.
In a steer or heifer it's a tender cut that cooks in 2 to 4 hours. Sear fat side down first after drying well to enjoy its distinctive prime rib flavour.
After you buy meat weight doesn't matter for SV cooking, just thickness. 1.5-inches is the usual thickness. A lot of it is fat, likely the reason it's hard to sell.