Apparently, the examiners use the CRP-5 when setting th exam. I bought one with the wind arm on the strength of advice from Pruners, however I could not tell you whether the wind arm is worth it or not. I would say, however, that I took mine back because the quality of the print was not very good. Pooleys were very good and sent out another the same day, however, this one is also not the best bit of printing I have ever seen. When you pay £70 for a few bits of plastic with printing on them, you do expect the printing to be A1. You can also try E-bay, but the ones I have seen on there generally go for about 90% of list price and most e-bay vendors seem to charge a lot for postage so you can end up paying the same for a used product.
I have 2 pairs of DC headsets, they are great but I have never tried noise cancelling jobbies, if you are going to spend time in the US hours building I imagine that this could be an advantage flying day in day out.