Agree Rudy. You would think a "custom shop" would at least match up the body panels.
I guess if someone had to open up the roof the better way would be a T-Top. That would allow you to retain the spine and the ridge for stability and I think it wouldn't be as extreme a look (like the roof was just hacked off) as the targa. If someone could figure a way to add a spine to a glass sunroof that might be another way to approach it. The few sunroofs I've seen here have been flat and that breaks up the roof ridge which to my eyes is one of the focal points of the car.
Personally if you need fresh air that bad stick your head out the window or by a roadster.