Cool. I'm excited for your build. As long as the frame is straight I wouldn't worry about the dents. A frame with some nice paint chips and minor dents make you not care as much about using it to the max. The frame looks sweet and those dropped chainstays are very cool.
Looks like original spec for the fork/headset was 1 1/8 threadless, correct? Seller gave you some headset cups you'll have to knock out.
Regarding forks, Surly is probably a good idea, as they have a variety of 26" forks. You could put a Troll fork or a Long Haul Trucker fork on there. Soma also has a couple 26" forks but they don't look to have any mounts besides fender mounts.
I have an old mtb with a Crust Bikes Clydesdale fork that I would highly recommend. Meant for 26" wheeled bikes. A bit beefier than a standard fork but if you are planning on truly doing off-road touring then it will provide way more cargo capacity than a standard fork. I can attest that the bike handles entirely normally with it on there.
