First off, I say go for it! the silk and dope that is.
It is an art form, as mentioned earlier, but then so is building isn't it?
One VERY important note that wasn't mentioned is, Humidity. This will kill your finish. You want the air to be as dry as possible, so summer time finishes will look best. If not, the moisture will blemish the finish with cloudy spots, so do this to the entire piece.
Also Don't worry about color. You're using fabric and it can be tinted. "Rit Dye" is what I've always used. Cheap and easy to use. I have always used the powder form that can also tint plastic (like your canopy). I under stand the liquid dye cant do the plastics, but I never tried.
Dharma Trading is The best place for ordering silk. They are very nice and cheap. As for the the Dope, look into Aircraft Spruce and Specailty. I was told that they are the main manufacturers of the stuff, so it will be as fresh as you'll get. I know Brodak gets their dope from them.

Good Luck!!

DM