I use KoJel, which is jello-like but contains no gelatin. The ingredients are sugar, carrageenan, adipic acid, potassium citrate, natural and artificial flavor, FD&C Red #40 for the strawberry flavor.
IDK if the natural and artificial flavors would be an issue, and there's no info. about potential xcontam, so IDK about shared lines.
Making it is easy: boil water, add mix, stir, then chill in fridge. It sets faster than gelatin does.
If you want to call KoJel to ask, you can call 800-83-KOJEL (56535) It's made in the US, and it's kosher.