I'm shooting for a year. I was putting it on jack stands June 20th, and I got the frame back from powdercoating this week. So I got the truck stripped in about a month & a half.
The easy answer is if you can work 6 hours a day, 4 or 5 days a week, you can get it done in around a year (depending on the degree of restoration).
If you work an hour after work, and 6 or so on the weekend, I'd say between 3 - 5 years.
And get ready for the body work. If you're working under scenerio #2, it'll probably take around a year.