How Many: at least three
How Long: max 1 ft, min 1 ft, so about 1 ft
Threading: It could go either way, but on one end would be good enough
Budget: no idea
Quality: good enough that the threads will last more than a year, and that we can screw a bolt into it without it puncturing completely and/or break the pipe.
The whole elbow thing is good idea, but just using the normal pipes would work too, so see "Budget". I like the idea, but it's not necessary.
Edit: If you were to do the whole elbow thing, the pipes would have to be smaller than 1ft.