Personally i'd either go 150 or 250. Just so i could get a Double ended (DE) bulb. I'm not much of a fan of the Single Ended (SE) bulbs, though they do come in all wattage sizes and work fine. DE bulbs just seem to be more efficient being fired from both ends.
About that auction, a few things i would question or think about. They don't give much info on the ballast, probably one of the most important parts of a light fixture. Electronic or magnetic? It says its the correct wattage rating but is it? Also, the lumens, its a 20k bulb. Which is fine, though its more blue in color and will not grow coral as well as a 10k would. 14k is a good mix of blue and white....and what i run on my tank. And 10k is more white then blue.
Also another thing. That auction says nothing about a UV Glass shield...a need for any MH.
Its decent i guess, considering bulb is included. You should also take a look at
HelloLights. Thats where i got both of my 250w MH Retrofit kits from. Each for about as much as that buy it now price, though not including the bulb. But this way i knew exactly what i was getting and got to choose my bulb.
Have you thought about how you are gonna mount it above the tank? Sometimes its worth it to invest in a premade fixture if you have no way to mount a retrofit kit.
