Sounds a bit expensive for what it is.

Keep in mind that fluro's are like lumber, the sizes they are called seem to have little to do with real world measurements.

In your case you can fit two of these in there.

Hydrofarm - Hydrofarm FLT52 Single T5 Fluorescent Fixture with Tube, 24 inches

If you do it like this: 23X11 CAB Light Squeeze

I love those little T5's. You can put em all over the place. You did not say how tall your cab is so you may be able to add one to each side too.

Use reflective lining and you are good to go.

HTH