When you get to San Antonio, go to any H.E.B. grocery store. You can get discounted tickets at their customer service center. You can get season passes there for less than the cost of two visits to Sea World, which is great if you want to spend one day doing the shows and another doing the water park. Once you get to Sea World, you go through the season pass entrance where they'll take your picture and give you the carded pass that you can use to breeze by the lines the next time.
We stayed at a Drury Inn a few miles away and really enjoyed it. They have suites with a separate living room, so you can stay up late or wake up early and not wake those still sleeping. The one where we stayed, Drury Inn & Suites Northwest, had an indoor pool, free breakfast, and they even stocked the room's microwave with a bag of microwave popcorn and free sodas in the fridge, and they have evening complimentary beverages and snacks in the lobby. It's not as close but not as expensive as the Hyatt and some others closer to Sea World, and we all loved it. Some good restaurants, like Alamo Cafe, are very close.
Have fun with Shamu!