If to maximize earning potential while having the ability to enjoy as many different places in a four/five hour drive, DC might be the best bet.
If to maximize earning potential and live in sweltering heat, Houston would prolly be the best bet. I've family in Houston and Austin that are doing quite well there career-wise. In fact, my bro is a project manager on telecom and IT projects. Right now, he's with a large petroleum company.
Outside of that, what does your son think of you leaving the ATL?