I have a site that allows customers to view their account information and make payments.  Currently, I have a windows application that connects to the site's database via an ipaddress and updates the customer account information nightly.  This process usually takes 2 hours to complete.

I'm planning to move the site to a new host and many of the hosts won't allow me to connect to the database via an ipaddress.

I'm wondering if anyone has any recommendations on other methods to do this.  Other methods I've tried in the past seemed to be slower.  Some of the methods I've tried are:  (1) the windows app ftp's a file and the executes a webservice to read the file and update the customer accounts  or (2) windows app connects to a webservice and passes each account as parameters and updates the database.

What would you recommend?