I need a more business/job/hi-tech area - I thought SA being lower tech, it would be easier for a tech guy to be a "big fish in a small pond" - I was wrong. Very few jobs and lots of people I worked with at Citibank were grossly underemployed - but happy to have jobs.
You may wish to also consider Austin - not too far up the road, and VERY big into high-tech. The city is fairly well laid out, it has a smaller population than SA (let alone Houston), and is a pretty good place to live, all things considered. Since you lived in the PRK, you will doubtless find it easy to ignore the great number of idiotic liberals </oxymoron> that are attracted to UT-Austin and the government.
Back to SA vs. Houston - the building of the Toyota plant and PGA village will spur economic activity here in SA. Anyone who believes that SA's economy is almost entirely dependent upon partying and tourism is not only wrong now, but will be even more wrong as time passes. PGA Village will bring in a lot of money from retirees and spur the services that they use - which, in turn, will spur even more activity in other areas of the economy. Toyota will not only directly employ about 4,500 people in a couple of years, but its suppliers that basically must locate themselves close by will probably employ 10,000-12,000 people (again, directly). Add to that the services that must be built/enhanced to handle all of those folks (schools, hospitals and medical facilities, construction, food and merchandise shopping, etc., etc.) and you have the makings of a boom. Something like 150,000-200,000 folks will live in SA in 10 years who otherwise wouldn't have...and that is without ANY other big company than Toyota deciding to build here. There are rumors that Honda is also considering a move here, which will further stimulate the economy. This makes sense - if one of the top 5 largest businesses in the world decides to go someplace, lots of smaller businesses are going to give that place a look. All of those people, and the businesses that they work in or support, will require lots of IT work. Other, existing businesses, will need to continue to upgrade, or be passed by (which, of course, applies anywhere).
Trade with (primarily) Mexico will continue to provide a further jolt to the economy here - its effect will only grow.
As to why SA's bright future should impact you NOW - the longer that you are in one particular place, the more people you know and the greater your chances of doing well. Staying here for the long term will be of great benefit to you. Regarding being a big fish in a small pond - I'd say that this is about impossible in Houston or any other mega-city. You are better off in this regard in either SA or in Austin.
Again, the best of luck to you and your family - no matter what your decision.