"T" Hooks & Forged hooks, See pictures.
Most of the time I like and use Grab Hooks with a chain. That prevents loads from sliding around. Also I make almost everything needed or wanted.
The hooks on the top of my bucket are hand forged out of RR Spikes. Before you bad mouth RR spikes as poor metal, they are a little harder than mild steel, better than most "Cast Steel" and some Stamped or forged hooks. They have also stood the test of time & load. On an up pull they are strong enough to lift the back wheels off the ground.
They could have been forged to Bolt on, but then you are dealing with bolt strength. Welding to a plate and bolting it on is a good option, just use a good grade of bolt and 2 or more.
"T" Hooks are good for a moderate load and can be had with different load rating. They will work best on the ends of the bucket instead of the top. I have looked them up on the net and could not find any that came with a "hook" all had loops on them. Buy hooks seperate, cut the loop and re weld it. Cut a "keyhole" slot that the T just fits into. I use them fairly often on the back hoe bucket for modest loads. If your bucket is on the thin side Weld on a steel plate for the keyhole.