While I was born in Houston & raised in the Woodlands area, my job has kept me exiled in California for nearly 8 years now.
While I haven't tried the kites you're asking about, I do have some other helpful advice that, while applicable anywhere, is based on my personal experience back home.
1) Good, consistent winds are hard to come by. Either there are trees or buildings that are generating all sorts of turbulence. The lighter the wind, the worse the turbulence will be.
2) If you read the National Weather Service's forecasts on the wind, immediately take 5 mph off the stated wind speed for most locations (because of #1). This is especially applies during summer. When the forecast said "5-10 mph", it meant that I would have to just pull out the boomerangs and forget about flying. At least until I bought a true ultralight kite.
3) If you can, get out to Galveston or some other huge, empty coastal field to learn. That way, learning will be fun, and not a drudgery.
Just remember - this is all about having fun - especially if you're trying to get your boys involved.