Is it possible to have two carts?

I'd like to start using Zen Cart but have a question.

We have two distribution centers, one on the East coast, one on the West coast. We need our customers to be able to enter their zip code to calculate shipping and then have the cart automatically determine which distribution center is closer (better shipping costs) to the customer. We then need the cart to be able to download to FedEx/UPS and QuickBooks.

Is this possible, or am I going about this all wrong?
Thank you for your help!

You will probably need some customized coding to make the determination, and possibly cloned and customized shipping modules for each.

I would think you only need two separate shipping modules. East and West.
I shouldn't be too hard to have some script that then displays the lower of the two.

Also, the zip ship mod
http://www.zen-cart.com/index.php?main_page=product_contrib_info&products_id=463
offers the ability to designate separate zones and which zip codes ship to each.