LTH,
I see beef knuckle bones regularly at Treasure Island, Fairplay and Pete's Fresh Market. In all three cases they have usually been quartered on the band saw. Only difference being price.
Chamorro (shank slices) would also be an excellent choice, as it is meaty. Petes, Fairplay and every Mexican market in town feature this cut for
Caldo de Rey.
Try skipping the roasting of the bones next time you make beef stock. Less work, no bitterness which sometimes results from roasting, and you still get nice color from roasted mirepoix and tomato.
"Bass Trombone is the Lead Trumpet of the Deep."
Rick Hammett