I hope this gets stickied, because the question is asked between 5 and 12 times a day. It's a legitimate question... I don't mean to condescend.
How to Carbonate Sweet Cider:
Cambden Tablets do not stop fermentation.
Potassium Sorbate does not stop fermentation.
Sure, the French have their Kieving methods, and other advanced methods exist, but for the first-timer, this is intended to be a guide.
1: Pasteurization
See here...
https://www.homebrewtalk.com/f32/easy-stove-top-pasteurizing-pics-193295/
2: Force Carbonation with a kegging system
After cold-crashing and adding potassium sorbate, you can stabilize the cider and ensure fermentation doesn't restart. Neither cold-crashing nor sorbate additions alone will stop fermentation while it's still sweet, in most cases. Slow it down, yes.
3: Splenda
Let your cider go down to 1.000, totally dry, then backsweeten with an unfermentable sugar like Splenda and use the standard amount of priming sugar for the yeast to turn into CO2 in your bottles.
The attenuation of your yeast strain is irrelevant to the subject of cider. Consider any of your yeast options to have 100% attenuation. Do not be under the impression your yeast choice is going to 'poop out' at any particular gravity level.
For assistance in yeast selection, among 100 other items... see: https://www.homebrewtalk.com/f32/results-juice-yeast-sugar-experiments-83060/
How to Carbonate Sweet Cider:
Cambden Tablets do not stop fermentation.
Potassium Sorbate does not stop fermentation.
Sure, the French have their Kieving methods, and other advanced methods exist, but for the first-timer, this is intended to be a guide.
1: Pasteurization
See here...
https://www.homebrewtalk.com/f32/easy-stove-top-pasteurizing-pics-193295/
2: Force Carbonation with a kegging system
After cold-crashing and adding potassium sorbate, you can stabilize the cider and ensure fermentation doesn't restart. Neither cold-crashing nor sorbate additions alone will stop fermentation while it's still sweet, in most cases. Slow it down, yes.
3: Splenda
Let your cider go down to 1.000, totally dry, then backsweeten with an unfermentable sugar like Splenda and use the standard amount of priming sugar for the yeast to turn into CO2 in your bottles.
The attenuation of your yeast strain is irrelevant to the subject of cider. Consider any of your yeast options to have 100% attenuation. Do not be under the impression your yeast choice is going to 'poop out' at any particular gravity level.
For assistance in yeast selection, among 100 other items... see: https://www.homebrewtalk.com/f32/results-juice-yeast-sugar-experiments-83060/