I have both the Tubus Tara and Duo front racks. If your fork has through-the-fork braze-ons, I suggest checking out the Duo. (My Nor'wester has single-sided braze-ons, so I had to get the Tara.) It's a very simple design, basically just an S shape, and does not have a front hoop. I like it for my S&S bikes as it makes packing really easy without the hoop. In fact, I just put it back on my bike this afternoon as we're leaving for a bike tour in Europe next week.
Spacers definitely help on the front racks. You can find a variety of cheap plastic ones and longer M5 bolts at most Lowes and Home Depot stores in the loose hardware section.