Do they still make fanny packs? I haven't seen them in years.
If you are going to Disney, you might just want to get a pattern for a money "belt" something that can be attached to you to hold just cash and cards. I don't know how old your kids are but you might also want to consider a stroller bag attachment for food and drinks and medical supplies. ie band aids sprays sunblock, aspirin and any other pill things that you might need in the park. even if your kids are too old for one you might want to get one of those umbrella ones to just "carry" all the stuff that you might accumulate or carry.