If you have a comfortable boat that you can take the kids on and wife without being miseable or worried to death about a capsize or the kids falling over, you will use the boat more and be much more happy. Period. I am a father and raised (and still do) my kids on a boat. Giu and others are right: kids on a boat is no big deal. You just start early with the rules and don't waiver. Review other threads for kids on boats. Myself and several other members that have raised kids on their boats have put a lot of info in there for you to review. If you have any questions, you can re-post here or PM me.
I would buy a Catalina down there. That is Catalina country and a very popular boat. Sea Lake is a good broker around you and very knowledgeable. Ask for Brad. I have never purchased a boat from them, but have had many dealings with them at shows and elsewhere. They are one of the better brokers on the gulf. They also sell many boat lines (not just Catalina) and are actually skilled sailors (WOW... what a nice change!!).
I think a Catalina will hold its value down there better than probably any other line that is comparable.
The Catalina 30 is a good choice. The 28 is a smaller boat, but for the money the 30 may be better. I would also tell you that the 32 is one of the best sailing boats under 35' I have EVER been on. The kids will be comfortable, the wife comfortable, air conditioning, big boat systems, small boat handle.
If you buy a sailboat down there that does not have a motor, especially not being a skilled sailor, you are insane. You will be dealing with the freighters that cannot manuever and Sea Rays that just flat do not care. The hard part of being on the "ocean" is NOT the sailing, it is the manuevering and waterways and learning to avoid the traffic, etc. My opinion.
I know T reccomended a trailerable boat. I have owned one too. There are exceptions to the rule, but my opinion is that trailerable boats are really used for about the first month or two, then it is so much of a pain to move it or rig it that they start getting neglected and un-used. Now, you can put your trailerable boat in a marina... but then why did you buy a trailerable in the first place? Full keel heave non-trailerable boats will sail better and are more stable. I would avoid all water ballast.
If you want to spend a lot less money and get the feel for sailing, try a Catalina 250. It is trailerable, but I would not use it as such. It is a nice sailing little boat and will get you used to how they handle. The family can go down below and lay down. It has a head and small galley. It really does not have the big boat systems, but it is affordable. THere is also no air conditioner, unless you rig a top-mount unit.
In boats, everything is a trade-off. With the young kids and responsibilities you will be faced with (in time, if nothing else), buy a boat that will make it EASY to get out with the family on... not just an escape when you can get a babysitter. A little time on the h2o with the kids and wife, you will become experts and be comfortable. You just have to take the time.