Commercial body types are typically the best meat rabbits, depends on how developed the breed is in your area. Most common are New Zealand and Californian. Most people dont recommend small breeds or giant breeds for meat purpose. Small because there isnt as much meat. Giants because of the feed bill vs final product (large bone mass not as much meat). I'm kinda partial to Californians, use to show them in ARBA for 10+/- yrs still have a few left. Also had Rex, I can say if your laxed on butchering and dont always do it on time, the rex were more tender if done when older. Plus Rex have the nice soft pelts if you want those. Diet is important, if just feeding them to fatten them up, thats exactly what you'll get, more fat not as good meat. Number 1 mistake I've seen with rabbits is people "suitcase" (or scruffing) them. Meaning picking up by the shoulders. Doing this separates the protective membrane between skin and meat. Bruises the meat and creates flabby shoulders. I've examined this after butchering, it shows. My grandpa ran a slaughter house and his partner was a state meat inspector so i've learned alot threw them. ...and im talking about rabbits on a chicken site oh dear haha
Hopefully it helps!