AC Delco Professional brand vs. others, and brake drums

[dmjlambert]

When picking brake drums for a 1969 CST-10, what is your opinion about brake drum maker? I see there are several brands of AC Delco, such as Professional, Advantage, and OE. What do I get if I go up to the Chevy dealer?

What about getting whatever drum the guy hands you across the counter at O'Reilly's? Since the USA doesn't manufacture anything anymore, does it matter what brand? I see pricing of drums is anywhere from about $32 to $49 per drum, not sure what the differences really are.

When selecting a drum for the truck, if the new drum does not have the groove for the harmonic noise reducer spring that wraps around the drum, does that mean that drum is designed so it does not need one? Or is it best to make sure the new drum has that groove? I really don't want to replace the drums just to find out I've added a groan to the stopping.