is this light good?

Hey I couldnt see the light from the link...but I assume youre talking about the aqualight with 2 65watt bulbs over your 55 gallon as you said that gives you 2.3 watts per gallon which is good and enough to grow low-medium light plants....but no high light ones. Most plants with red coloring will not stay red under that lighting...so choose your plants carfefully. Any type of sword plant will be fine for you. You will also need to serously think about injecting carbon either through suppliments like flourish excel or bubblers. Dont forget to add root suppliments as well.

for a 55g I'd buy 2 shop lights and have 4x 40 watt bulbs over te tank for 160 watts or 2.9 watts per gallon which is good 'n plenty to grow alot
Look at this website for inspiration
http://naturalaquariums.com/

The link isn't working for me. If you've got a standard 55g, you'll need a 48" fixture to get light over the entire tank (a 24" fixture will only light the centre, leaving the sides dark, not attractive or very useful IMHO and confusing when it comes to WPG since part of the tank will be higher light and part will be dim). One of the most economical methods is to use shoplights as SF suggested. Shoplights are great for four foot tanks - they're designed for 48" bulbs. You can find innovative ways to hide them behind a homemade hood if it's a display tank and you find them unattractive (some are nicer than others).
If money's not a big issue, I'd go for a 48" power compact (PC) fixture like the Aqualight or an Orbit or Satellite (though these are designed for salt water and you'll need to swap out the actinic bulbs for something between 5000K - 10 000K). These fixtures are designed to be placed over glass tops.
If you're planning to grow medium or high-light plants and want to inject CO2, I'd aim for 3WPG or so. If you want a low maintenance tank, shoot for somewhere near 2WPG.

Yes it's a good light. It's the same one I use for my 29 gallon. My plants are not complaining and in fact I am pruning every week. I bought mine from Big Al's online. Here's a link. It's cheaper at Big Al's by a buck and shippnig costs a little less too. Yes, I am that cheap. Order on Wednesday and get double VIP points that earn you discounts.

For many things, www.ahsupply.com has the best setups, IMO.

For a 55g, I use 4 X 40w shoplight fixtures from Home Depot. 160w total. It was pretty cheap, though I can't remember how much it cost at the moment. Grows most plants. There are pictures in my signature of the tank and you can see things grow just peachily.

As mentioned, you'd want a longer light than the one you talked about. With that short light, the sides will be dark and the light distribution will be poor (ie cant grow anything on either end of the tank).