Are there any 3rd party freight estimators that work in MS? Can you access the cart weight from the shoppingcart.aspx page?

Here's the issue:
We don't have source code. We need to do real time shipping rates AND offer in-store pickup. The ADNSF estimator only shows "In-Store Pickup $0" since it's the cheapest option. This clearly should be ignored by the code since no one is going to use the estimator if they are picking an order up.
I'm looking for another option to use. I realize you can narrow down the in-store pickup option by zipcode or state but that does us no good.

Thanks,
Jason