Lighting for my Burmese Python

Question
I just built a cage that is roughly four feet tall, five and a half feet long and four feet wide.  A little big I know, but I built it so that I can adjust the size for when she gets larger to prevent having to find a new cage for a few years.  Anyhow, I purchased a fluorescent terrarium canopy from a local pet store that houses three 26w bulbs, and another canopy that houses two 26w bulbs.  I read somewhere that they need to be a certain distance from my snake to serve their purpose, but the box says nothing about it.  I'm concerned because at the above listed dimensions, the cage is at it's smallest.  Thoughts?  Also, I was curious if a fixture from Home Depot (a shop light with fluorescent bulbs will work instead of the canopy I purchased?  The canopies are rather costly and if I can take a cheaper route, I'd prefer it.

Answer
Hello Steven,

Wow, keeping a Burmese will be challenging!  
Which tube fluorescent bulbs did you get, which brand?  The bulbs should be far enough away to where he can't wrap himself around it.  Usually 6-8 inches is recommeded for most reptiles to have good UVB exposure.  Are you using a basking bulb?  
A shop light would work just fine, actually.  You can adjust the distance with the chains that come with it, too which would be helpful.  
Do you have pictures of your tank & of your python?

Tracie