gomberg kites makes tube tails in different lengths and diameters. They make one design just like the prism tail in your post.
Yes you can join them together. A hook is on the end of the tail that you can attach a 2nd tube. Looks OK but creates a lots more drag. I have sewn two together it looks and flys much better.
Gomberg is a good option as they do custom orders so you can get what you want. Like matching the colors of your kites.
I would go 100 in length.