my company sells vertical doors and most of all the companies have the same build quality. as far as the fender problem, I would say that each kit differs, if you are referring to the "Vertical Doors" brand they open out like stock for about a foot like NORMAL then go upwards. If you have extended fenders (wider fenders) it should help accomodate the vertical door kit. Hope this helps.
As far as the Sorcery Door Conversion, I have no experience working with their products nor have I inspected their product.
However to determine a quality product I would recommend making sure they have a warranty on their product, have it installed professionally by an experienced body shop, inspect the shocks that hold up the door, if they are weak or not a reputable brand they can cause the door to fall down (you do not want that!) or sag after you extend them up, and finally be sure to check the weld quality on the door hinges if they are not heavy duty or quality welds it will probably cause the door to be loose and most likely either break down slowly or need reinstallation (also make sure that the hinges themselves are think pieces of heavy duty metal). Good luck whatever your purchase you will definately develop some excercise lifting your doors.