I definitely recommend moonlights! I just got a set to put onto my tank, and they look fantastic!! All the reasons above are very correct. I actually purchased the set from a guy who posted about them on here. If you do look into getting them, do a search on this website for "moonlights" and type in the username of JRic999. There, you will find who I bought my lights off of. I highly recommend purchasing them from him if you do decide you want them. He gave me a wonderful deal, set-up a custom set just for me, and the quality and price is excellent. When my camera is fixed, I am going to post some pics on here as well.
As to the nitrates, it might be okay, but lower is always better. Start off slow, and add some mushrooms. See how they do. Continue to try and bring them down to whatever means possible, and if you cannot get them down, find why they are not coming down. Is your tank too highly stocked? Are you feeding too much? Is your equipment enough to handle what you are trying to keep in your tank? That's the stuff I would look at first. Find what is bringing the nitrates into the tank. I don't see why hardy stuff like mushrooms, leathers, and polyps won't do okay though. With those amounts of nitrates though, they may not grow nearly as fast as they should.