I don't think longer pins are available as lengthening would affect lift capacity and damage attachments. Sounds like you need equipment for a big tractor...
According to the product description, it is straightforward and does not require drilling or welding. The top hook has 5 adjustable positions to fit most accessories.
The product description does not specify if mounting hardware is included. However, it mentions that the top hook has a 5-level adjustable position and can be adjusted using bolts.