Lighting upgrade questions

[kmartcwby]

I currently have a 55g that I got as a starter kit, link of it is below.

Top Fin® 55 Gallon Starter Kit - Aquariums - Fish - PetSmart

I am wanting to upgrade the stock lighting to help my plants. Do I just need to buy new bulbs, or do I need to replace a lot more of it? I don't really want have to replace the covers that it came with, hoping there's a way to upgrade with what I have to work with.

[MrBeta]

Well if you want more light, you will have to upgrade the fixture.
What kinds of plants do you want/have?

[kmartcwby]

I have a few amazon swords, and a few others, plus I would like to be able to add some more.

The enclosures that the stock lights are in are 22" wide

[Rhino]

Look at fishneedit fixtures. Two bulb and four bulb options and you choose your bulb combination at no additional charge.

[kmartcwby]

hmm, all they have are 24" fixtures. With what I have, I need something that's a max of 22".

from looking around, compact fluorescent may be one way to go, the 55w is 21". Is there a best place to get these, if they're any good?