Congrats on your new EA toys. I am in a pretty much the exact same situation. I just had 8-9 acres clear cut (except for 30-40 scattered mature hardwoods). The cut was red pines , row planted 6-10 feet apart and never thinned. They were 60' tall and 8-10 inch, falling over like tooth picks in the wind by the day so I had no choice.
Just received my EA 60" root grapple and I have the EA 72 inch landscape rake on the way(Sounds familiar??).The grapple is a beast, well built, iron-art !.I know you have already orderd, but I had 2 cents to add.
My tractor is only 30 odd hp and 800 lbs lighter than yours but I will say to Spyders point, it depends on alot of things. Buckets are usually used in open areas, but if you eventually start swinging around the woods , you might appreciate a narrower grapple. Also going between stumps/trees, or other obstacles. Running tines in will go better with more pressure on less tines,but still pick up mountains of scraps with
I would call those guys at EA again just to discuss your specifics. It's not just about weight, price and width.They're so busy, I doubt they started welding yet. It's what will work best for all situations. 6 inches doesn't sound like much until you need 6 inches clearance. Don't get me wrong , if your going to be in wide open spaces forever then by all means wider is better.
I mow 2+ acres of grass and while the 72" Exmark zero turn was tempting me to buy,I went with the 60" and it still gets it done in an hour , getting around trees, house , playhouse, pool and all the crap mother puts out in the yard! and the push mower is in mothballs!
Either way , your going to love the EA stuff (Christmass in May!!), great people and great tools. Good luck and take care
Brian