anybody copy and make there own front coil over kit like alterkation

Depends on what he is doing. Just doing it for himself, 100% legal. Copying to sell them, maybe illegal (depends on if the person/company copied from filed for the proper intellectual protections) but it is definitely unethical.

As for everything else said by dukeboy and famous bob I totally agree with.
as far as duplicating something from someone elses design, all u have to do is change one thing on it , even for a patent.