I did a search in this thread and it seems that some people like the result from dry hopping with 0.5 to 1.0 oz of cascade or something similar. I'd also be interested in hearing about other experiences.
I just looked at my tasting notes from my first attempt at this recipe and it said to consider adding 0.25 to 0.50 at 0 minutes or dry hop. I'm brewing this on Friday and I think I'm going to dry hop with 0.25 oz of cascade and 0.25 oz of willamette, partly because that will use up all of my cascade and I have a bunch of willamette that I need to use up. I've also heard these two play nicely together. I do have 1.00 oz of citra that I could use instead.
Let me know how it turns out. I'm not brewing this for a few weeks so I'd be interested in hearing your feedback first.