Amazon is a decent place to start. If unsure about sizing, you can find sample packs on there too. As far as discreet shipping goes, usually, yes. However, I got a couple of the Rearz variety sampler packs and on the box was a label that read “Adult Diaper Sampler Pack” or “Adult Briefs Sampler Pack”. Something along those lines. There was a complaint about it in the reviews, but it was a while before I was looking at them and figured maybe they don’t ship that way anymore so I got them anyway. Mine had that label on there too. But, I had them delivered to a locker as I do with everything that I can since I’m in an apartment. Otherwise, buying directly from the AB/DL retailers will for sure get you discreet shipping.