if your planning on dismanteling the car and building it the way you want then y not save a couple grand and do everything the right way. I would go with the 69, especially because pro-touring builds can get pricey.
Mostly because of all the engine/trans work he has done already.. If i go with the 69 its gonna be a lot of money into an engine/ trans/rear end etc.. Going to look at the 70 this weekend to get some more info