We have a list of service providers on our website. Maybe you should contact them directly to help you.
We can not give more hints if you do not share the localization requirements of oyur countries.
Maybe you will be intrested on reading the How to create your country localization module for accounts topic to learn how to configure taxes and reporting.
Also there is the Spanish SII and French Chorus modules which are used to send the invoices to tax authorities using a web services. Maybe that is similar to what you need.