Welcome: You title your post as a 69 shell. For the budget minded, it's the best way to go. Also, unlike whatever you buy that has already been done, you have complete quality control over the build, with budget being the only restraint.
When you start with a shell, it's not like you're chopping something up, and if you have been lurking around here, you know that under these circumstances, the majority will agree that you should build it as you see fit.
T/A clones are nice cars, and they pay tribute to the era. Of course the colors could have been better, but they were about the best that the had to offer in that era. Modern day metallics do wonders for the car's lines, and unlike factory correct colors, modern metallics create natural "pinstripes" on the various crowns in the metal.
Look around and you'll see what I'm talking about. For the first 15 years the paintlife on my car, I had a lot of people stop and say, "Old cars don't do a thing for me, so I never stop and say anything to the owners. But your car is one of the most georgous things I have ever seen."
If you want to impress a judge, do it the way you're "supposed" to do it. If you want to impress everyone, do the car in modern day metallics.