The only sure-fire way to beat goat-heads is to go to...well you already know. Nu-Tecks. That being said w/much risk
my experience w/SMPs has been very good. We don't have GHds in Mid-TN, but I ride consistantly in the 'stone zone' as the shoulders on rural roads aren't very wide. I use 28mm on my Motobecane Fantom CX 'loaded commuter' and 25mm on my 'light days'(maybe not a good choice of words)singlespeed conversion. Got them @ biketiresdirect for 35.00 per. Tried to order another pair, but there was a disclaimer on the webpage...something about a fire a/t warehouse. AEBike has them for sure, I checked bf posting. 25, 28 and 32mm. Have over 2500 combined miles w/no probs. They're heavy, but have light rolling resistance compared to their weight. I'm in the process of re-fitting ALL my bikes w/SWP after being a Nu-Teck guy for years. You wont need Mr. Tuffys or Slime w/SMPs. They're worth every dime IMHO.
BTW, they're a little trickey to mount, but you'll figure it out pretty quickly. The reflective sidewalls are pretty sweet, too for night rides.