MarketPress: Shopping Cart Layout Design

How can I change the layout of the Shopping Cart Page. I'm running into a few problems with Marketpress and need to fix as soon as possible with a cleaner look.

Problem is that Shopping Cart Page fields seem to run together. Would be nice to even add borders to get a cleaner look.

What files and what type of code do I need to adjust to accomplish this task.

weblink is http://www.kausvideo.com just add something to the cart and when you go to checkout you will see what I'm talking about. Need more space between certain items etc...

Thanks In Advance!