I'm a big fan of Craig's car. It started out as a '75.
http://forums.pelicanparts.com/porsche-911-technical-forum/646800-my-backdated-hot-rod-project-underway.html
I think one of the reasons that 74-75 have gotten as "hot" as they have recently is the 50 states smog exempt status. Many places outside California (and Colorado) are also exempt on the 76-77. Makes the cars ripe for an engine swap from the power standpoint. And getting the longnose is really quite straight forward when it comes down to it.
The cars generally have better brakes, mounts for sway bars, aluminum control arms, 915 gearboxes without the mainshaft seal issue, galvanizing, and a bunch of little things that were factory improvements that don't need to be done to them before you dig in.
For me personally, I was really into the longnose look for a long time. I don't know what happened recently, but I'm in impact bumper mode now. The '74 I just bought had a slantnose on it, so I really was able to do just about anything with the car. I picked stock looking, with standard 1974 911S trim with a single exception, SC rear flares. Other than the 7&8" wheels, and those flares, the car is going to look stock on the outside. Long term it will be the mechanicals that get the full once over to make it drive as good as it looks. I'm just guessing, but I suspect when I am "done" I'll be into it for close to $50k. Thank dog it's only half that up front and I can put $5-10K into it yearly for the next 5 years while I enjoy it.