I believe Splendora is near Houston. If you can always count on getting consistent rain, you can make it 10 to 12 ft. deep. However, if you aren't sure what to believe about the future of rain, make it 16 or so ft. deep.
As for stocking, forget about the crappie in a small pond. Catfish and LMB are ok but you have to figure out what you really want, how much work you are willing to do, etc. The oft repeated question is, 'What are your goals?".
Welcome to Pond Boss. Read the different threads here, subscribe to the magazine, and buy the Raising Trophy Bass book by Bob Lusk.
Keep your checkbook handy and don't lie to your wife. You'll get caught everytime.