Client does home parties and has basic fee plus mileage

So they have multiple parties that cost different prices. Client fills out a form selecting the party that the want. Than it looks at the zip code and calculates mileage cost based on how far it is from the office.

They have it working in Joomla but want to migrate to Wordpress. Any one know of plugin to do this? I'm almost thinking of setting up a shopping cart and than trying to fudge it with shipping but not sure if that would work.

Any help would be appreciated