I'm going to agree with Frank, with the curved side glass, the chop alone may run you your entire budget. Remember, as the roof gets lower, the side window openings change shape. In theory, you can sink the top into the body, but that would make the window openings look funny. Try cutting the roof off of a picture, then pushing it down behind the picture to see what I mean. The roof would not only get lower, but also shorter in length.
Shiny Side Up!
Bill
'72 442 "Inamorata"
'89 ASC/McLaren
www.FQuick.com/ProTouring442