Fibergalss will work fine but do not install a seperate storm door.
Contrary to there instructions not to do so, I installed a seperate
aluminum full view glass storm door which is interchangable with a
screen for summer months. Ya sure Minn. The low winter sun beat
directly on the door and began to warp it. It was a good half inch on
top and bottom. Quickly replaced the glass with the screen and the door
came back to square. I have left the screen on ever since. I guess i
should have read the instructions BEFORE I started. Also, go for the
factory finish. I opted to finish it myself. That turned out to be a
chore but it came out real nice.