Can’t specifically answer your question about Stinger as I have no experience with them. I have a 72” Tar River long bottom style. Weighs about 487lb per specs. A few thoughts to take or leave as you see fit:
1. Twin lids on a grapple 66” or 72” or more, definite yes. Loads aren’t neat, tidy, or evenly distributed. Independent twin lids is a major plus.
2. 72” covers the width of the tractor. Is that important in a grapple? Not for what I do with it, which is about 95% carrying logs, brush, and trash, but maybe if you’re root raking with it it might be important. 66” would save some weight; save some money; probably be fine for grasping and carrying stuff.
3. A comparable EA weighs about 10lb less but is probably better quality than mine. You can save more weight with EA by going to a model that’s narrower than 72” and/or a model recommended for less than 35HP tractors. If you go with a lighter weight less than 35HP recommended type model you might have to be a little careful with it. But, I don’t think you need anything more than the 400 to 500lb range. Past that you’re just wasting loader capacity.
4. Long bottom v root rake style. There are fans of both. I like the long bottom for moving brush and logs. It will root rake but not its strong suit. Vertical/root rake. Never used one. Some folks love them. Never heard anyone really complain about having bought the wrong style.
In the off chance you’re still reading…
I followed the link you provided in your post. The Stinger looks like a good match and a step or two up from the quality of mine, at least it appears that way on the web. 66” model may be a good choice. I think you’d find 56” too narrow at times unless you’re strictly loading logs on a sawmill or doing some other specific, limited duty.