at your weight and the conditions in dallas you will be on an 11-13m 90% of the time.
i would say go for a good 10-11m kite first and a good all around board like an ocean rodeo mako for your lake chop.
That doesn't sound right if he really does have local winds of "10mph with gusts in the teens". For conditions like that, you need a light wind kite (Blade Fat Lady, Naish Fly, etc.). But in reality, conditions that light are not good for learning and really aren't much fun for anybody. The best conditions to learn in are a wind speed of 15-25mph and that would indicate a kite size of around 13-14m for someone at 210lbs.
Keep in mind that once you really get into it, you will want at least 2 kites. A 14m kite for most days and a 10m for when the wind picks up.
If I were starting over, I'd probably be looking at getting a Caution Spitfire for a couple of reasons - they sell direct (less expensive) and are very durable (beginners crash their kites a lot).