Dovaka,
I was in the same boat as you with almost the same year car. I started building a sheetmetal dash for my 78 Camaro last week, and I must say, for my first attempt at something like this - it's turning out absolutley wonderful.
I started out creating a cardboard template of the rough design, and then proceeded to cut, bend and weld the metal to the shape I wanted. (Breaking the cardboard template into "modules" really helps with the fabrication.)
The only problem I encountered was the fact that the dash is 56" long, and our brake is only 48" long, so the curve at the top of the dash had to be done on a table edge with a 2x4, by hand. It acually came out better that way with a gradual curve instead of the sharp bend the brake would've put in it.
I'll post some pics of the dash construction later when I get off of work and go snap some photos of it.
It's really not as hard as you think. Just take your time and plan it out, measure twice and cut once.
The only thing I may have problems with is wrapping it in vinyl or something later on, so I may leave it bare metal and just paint it. (I found years ago that I am no good at adhering vinyl around compound and complex shapes.)
If you are interested, let me know, and I'll be glad to show you how and what I've done so far.
What kind of equipment do you have access to? Welders, Metal Brakes, ETC...?
~Michael