My first question is why are you doing it ? I did it still working out some bugs but I found my rubber brake lines where bad not my power master .
To answer your question I got mine from red regal . I had some probelms but he helped me work them out . I should have trouble shooted a little more becaue I am still fixing the issue that caused the problem . Red regal parts are used ,but in good shape . His instructions are worth the money alone . It would have taken alot longer without them . I am on my second master cylinder and if this doesnt work I will get a new one .