I've got a 4 runner and going to get a hitch mounted d-ring shackle and debating on something like this?
https://www.amazon.com/Driver-Recov...4&keywords=trailer+hitch+tow+shackle

What weight capacity should I get? I see some for $20 on up to 50 or so. Curb weight of vehicle is 4675 and I'm sure I've got a few extra hundred in there when hunting or driving in the snow.
How much capacity should I get, if I'm stuck, I'd love to have it be enough and thinking 13k or so.
Please learn me what you can

The one you linked to is rated heavier than your hitch is. I don't think you need to go heavier.

JonS,
You would also be better off w/a pin shackle compared to a threaded anchor shackle.

If you stretch the anchor shackle you will need a torch to cut it off.

A pin shackle once the hitch pin/retainer clip is removed it can be driven off the receiver.