dude just go with whatever they sell at like walmart and stuff. those kinda cheap tubes. other than sometimes landing on edges and stuff, they work fine. if you're worried, then dans sells some super thick tubes that have an outer edge thats like 5mm thick. and most cheapo tubes are like 1.5-2 mm thick.
most of the time when a rider gets a flat of no fault of his/her own, it's because something very sharp went through the tire. if it's sharp enough to puncture a regular "thin" tube, it will puncture any thick tube as well. otherwise, you can get pinch flats of you land REALLY hard on something.
if you get a flat any other way, it's probably user error- pinch flat from under-inflation, spoke puncture from wrong spoke size or lack of a rim strip, explosion due to customer being stupid enough to pay $40 for a KHE tire, etc.