Wattage is not the most important thing- sort of. The problem with watts is that is doesn't accurately measure the *power* of the light. It measures the power of the bulb, not how efficiently that energy is used. For instance, a compact florescent will produce far more light than a T-5 florescent, even if they are both the same wattage. The outdated "watts per gallon" standard is based on T-5 lighting, so you can't use it to accurately determine the lighting of your tank.
That being said, I highly recommend using compact florescent, it is very power efficient and the bulbs need to be replaced much less often than tube florescent (which needs to be replaced every 6 months). What you want is a light with 6,700-10,000k light spectrum, preferably a mix of both, as 10,000k is a bit powerful, but also very valuable for plant growth. What you DON'T want is anything 50/50 or actinic. These will not be very helpful at all for growing freshwater plants, they are designed for coral growth.
Flourish is definitely a good liquid fertilizer, I use it myself. However, you need to understand what fertilizer is for. A liquid fertilizer is for a plant that absorbs it's nutrients primarily from the water (not the gravel). Water sprite and java fern both do this, as do other floating and stem plants.
The Amazon Sword is a rooted plant, it demands a LOT of nutrients from the substrate. For that you can get root tabs, which you replace every 6 months or so. It's basically a little vitamin pill you stick under your plant's roots. Flourish makes plant tabs, I think they run about $8 for 10, which will last you a while if you only have a couple plants. There are also some cheaper generic alternatives you can order online. I use aquariumplants.com own fertilizer. It cost me somewhere between $10-15 (I can't remember) for 75, which will last me a loooong time.
I know you've gotten a lot of suggestions for lights, but here's mine. I personally have three 24" ones and I absolutely love them. It will provide more than enough light for the plants you mentioned, and leave room to add some trickier ones if you decide to later: http://www.marineandreef.com/Freshwa...p/res53014.htm