rsimoes,
I fully believe that your question is a sincere one, and I wish that I could tell you that you would get dependable advice on this subject on Club Cobra. However, a number of people who post here have a very pronounced agenda when it comes to the differences between Kirkham and Shelby,and truth is the first victim of said agenda. My advice would be to disregard 90% of what you hear or read, and visit both manufacturers in person. After you do this, I think that you will be very comfortable with what you decide upon.
As for me, I'll tell you that I couldn't be happier with my decison to go with Kirkham. Now disregard what I just said and find out for yourself.