Your best discounts will be shopping for dining gift cards at a discount for chain style restaurants at CityWalk. I got $90 of Bubba Gump cards for $65 through Sam's Club and $45 from Panda Express for $35. However, I don't really recommend either place. You can go to Confisco's for not much more than Panda in the park, but lots more delicious. I'd also choose Cowfish over Bubba Gump any day of the week. It's just overpriced Red Lobster without the garlic biscuits (best part of Red Lobster The only Universal cards I have seen are more vouchers for tickets only, not really a gift card.
You can pick up Universal gift cards at Walmart and Target in Florida, but they are full price. I think there are some places in Georgia that sell them. Also you can purchase them at the Universal Store in CityWalk and stores in the parks.