55 watt would do jsut fine. Also, chances are pretty good you could use either wattage bulb in your fixture. I have a 15 also and I love the proportions but I don't find the coverage froma single 55 watt to be that good, but the JBJ fixture probbaly has better reflectors than my DIY hood and the fixture with the legs is probably a little higher than my bulb. You would be fine with either, really. I'd go with the cheapest/mmost attractive.
No problem. I have pressurized and ferts, so thats all down.
I have 110 W jalli on my 15, and it sucks dodo. Its giving me brown algae, just leaving on only 1 55w light on, and its also giving me alot of other algae problems.
Thanks for all the replies, I guess I shall go for the 55w one.