The BD3 is limited to 18k lbs trailer weight and 3500 lb pin weight, so I’d consider the BD5. Always hard to know what the future holds, and you won’t want to upgrade later…they are pricey.
We have a BD5, and love it. It removes the shock that’s transferred from the truck to the trailer, and vice versa. Of all the upgrades I’ve done, this is by far the one I would never want to do without. Whether the cost is justified really depends on how much you plan to travel. If your rig is going from the dealer to a campground and never moving, I wouldn’t spend the cash. If you are going to travel the US, I wouldn’t be without ours.
When you order, they will want to know the brand of truck you have, as the hitches are configured differently for GM or Ford. They are the same hitch though, with the exception of the steel straps on the front and back. The end plates are merely swapped from one side to the other. I actually have a BD5F (Ford), but it’s in a GM truck.