As someone who has done something like this with a street donor (thanks G!) I can tell you the transformation to that all out Scrambler requires parts worth more than the donor. The above phase one is a better example and works just fine in the real world.
Up front I imagine you'd be better off with dirtbike forks internally shortened. That way you will get a bolt up front wheel, too, although you may want to lace up a 19" rim and toss a 320mm rotor on it for better street manners.
Gwynne, I have a set of old XR600 forks that I will happily donate to your scrambler project. They need new seals and oil, but might be fun. 43mm size, no idea how big your triple clamp is but I imagine you'll need a new one anyway, right?
Things got crazy busy . The good news is that the monster is in the shop and not on the roof but it is awfully dusty. Looks like it has to wait until winter