Hi there, and

!
That is a neat sized tank you are having!! I would go with two filters on it, just to have one filter fully working while cleaning out the other. That way you never risk losing too many bio bugs. If you prefer the hang-on filters that hang on the back of the tank, I would go and have a a look at the Aquaclear filter series. They come in different sizes, you would need 2 Aquaclear 300, which filters 300 gl each, and gets you up to 600 gl/hour, wh ich is perfect for this sized tank.
DrsFosterSmith.com, generally being one of the best sites to shop for fish items, right now has a sale on the Aquaclear filters.....
http://www.drsfostersmith.com/product/prod...09&N=2004+22769Compared to petstore prices, their regular price is already a steal, and now they are even cheaper.
If you prefer one of those filters that are under the tank instead of in the back, I don't use those, but there are plenty of helpful people here who can tell you all about it.
As for airpumps, one of the best, and very quiet, ones around are the Rena airpumps. They also come in different sizes, and are just perfect. They are strong, and you hardly can hear them. I bought my oldest one 5 years ago, and never had any kind of problem with it, and no maintenance work so far. They also are available from DrsFosterSmith.com.
As for the CO2 equipment, I don't have any experience with that (yet

For the light question, especially with live plants in the tank, I would go with at least 2-3 watt per gallon of water to have adequate light for the plants.
Hope that helps you a bit!