The reason dogs with natural tails have such a lot of variety is that the tails have been routinely docked for so long, nobody has bothered to take tails into account when breeding, so there is no real standard for what the tail should look like.
My dog's tail is what's usually called 'gay' -- i.e. upright and curling over her back. (cutting off tails and ears for cosmetic reasons is illegal in my country) Here's a blurry picture of her as a puppy showing what I mean. Most poodles here have tails with what I'd describe as a sickle curve, but I think I prefer my dog's tail more, because it has character and because it's compact it doesn't knock stuff over when it wags. Tail shape is hereditary, so if you want to know how a puppy's tail will look, look at its parents'. My dog's dad and her paternal grandmother both have gay tails.
Plenty of countries don't allow dogs' tails to be docked, so you could consider getting a poodle from abroad if you're having trouble finding a suitable breeder in your own country.
Her tail did 'uncurl' slightly for a while after she had been spayed. I assume the muscles she uses to hold it up hurt.
Additional: poodles being shown at Crufts with 'sickle tails'