My new rack! :) And questions about Flexwatt installation!

[tikigator]

Hey everyone! Well I quickly went from having 1 pet BP to a collection of 10 with 4 more on the way Tanks quickly became a royal PITA in every way possible...from the space issue to being hard to clean to heat and humidity problems. SO.....I went ahead and caved and purchased a combo rack from dragons4you.net (awesome prices, btw!) but it is going to take a couple weeks to ship....so I decided to beg my dad to help me build a rack. So I went and bought some melamine from Home Depot and had the guy at the store cut all the pieces (which was so convenient!) The shelves fit either two 15qt sterilite tubs, or one 32qt tub. And it's on wheels for easy movement. The only thing I need now is heat....and that's where I need some help....so 2 questions:

#1 back heat or belly heat?

#2 depending on your answer to #1, what size flexwatt?

I am trying to decide whether to do 4" belly heat across the back of each shelf.....or one strip of 11" right down the middle. Suggestions would be greatly appreciated Any any recommendations on how to install it would be great too---the back is easy to take off if I decide to do back heat. I have read pros and cons for both so I figure I would ask you guys and see what you think.

Here is a picture so you all can see my rack (I am so proud of it!! )