Hey Brant; I don't have any specific input regarding your question on aurora lenses, but we were in Iceland a few year ago. Knowing your affinity for waterfall photos I'm sure you'll have a great time in Iceland! (And some great hot springs to keep your wife happy I'm sure you've done your research, but make sure you don't just stay in Reykjavik: there is a lot to see outside the city area.

Stephen