We're in Houston and have had SW Annual Passes for many years. Whatever you do, do NOT stay in the La Quinta Ingram Park that's nearby. We spent 2 nights there last Summer because we got a rate that was too good to pass up, but we should have passed. Very, very scary place.
For years, we bid resort on Priceline and ended up at the Radisson or the Hyatt, but those days are gone, and we haven't found anything great to replace it. We have stayed at the Comfort Suites that's on 410 pretty close to the scary La Quinta and liked it just fine, and would stay there again.
We obviously enjoyed the park because we returned several years in a row. The dolphins are to the left when you enter the park. The dolphin & beluga whale show is called Viva and it is outstanding. Great music, comedy, animals, divers, etc. all in one show! Be sure to arrive at least 20 minutes early for the pre-show entertainment.
The week before Easter is Spring Break for much of TX, so I think it's going to be very crowded if that's when you're going. Just checked the park hours and they're open much later than usual, so that confirms that they're expecting heavy crowds that week. But they're open every day. You may have trouble finding accommodations that week also. Is that your week or are you looking at earlier or later?
Post back with any specific questions and I'd be glad to try to help.