If you were sticking to mainly on-road riding, then I would say slap a rigid fork on there and play around with the spacers. Thats what I did. But since you might do some off-roading...it is kinda of discouraging to know that you have to swap forks, brakes, and re-adjust the handlebars each time you switch.
So my vote is to get the delta extender and see how it goes. And I hope you aren't doing any extreme downhill or other high impact riding where this component might be under so real stress.