There are literally 100's of suppliers for a set of pallet forks. From Bolt on to your bucket, to weld your own kits. I know I agonized over this one a while and just decided to buy one of the best, even at a bit of a premium. Over 50 years of tool use definitely says, buy the best you can afford. Of course there is the used market as well, with plenty of excellent offerings.
For me, simple. Call Everything Attachments, talk to Travis. He'll set you right.
btw - Are you sure it is Deck Forks you are looking for? A Grapple would be a much better tool for cleanup, and oh so many things.
Good luck, and don't worry, the gang will be chiming in in no time with plenty of excellent suggestions