Good question - I'm in Canada, and i cn tell you right now it won't be Home depot!
Try some of the smaller hardware stores, many times you cannot tell by looking at the clamp, just by testing one or two or bringing a regular one as a comparison
I have found that if you take a pool store clamp with you to compare, you may see subtle differences on the clamp like a slightly thicker band, a better crimp connection for the worm drive screw, little telltale signs like those are what you're looking for.
be prepared to hit a number of stores til you find good ones.