Champagne is carbed to about 5-6 volumes of pressure, about twice that of beer or most ciders. Not positive, but I think most beer bottles aren't rated to hold this much pressure, so champagne bottles are the way to go.
Priming sugar calculators can help you figure out how much sugar to add to a batch
The safest way to make this would be to ferment dry, prime, and bottle. I'd avoid pasteurizing bottles with that much carbonation, but cold-crashing may be an option if you want to have some sweetness.