Replicating Invoices

My client is a company with many remote stores located in the different cities. They're unwilling to use citrix or other terminal service or remote database for the stores to get into the headquarter database as it requires a dedicated, expensive lines. They prefer to use a replication scheme where the stores have their own standalone database. So, at the morning, the stores will copy all the masters data from the HQ, then going offline during office-hours while they can make orders and invoices to their own database, and sending all the changes to the HQ at the evening. (I got a replicator software package that do almost the same as the SQL Server replicator service, you still need to specify what tables and data to be transferred, but the good point is it run under Navision).

What is the best strategy to replicate invoices? Copying all the data in the posted invoice table, G/L entries, customer entries, etc to the HQ database, or.... copy only the source document (in this case, orders) and post again locally in the HQ? Is there anyone ever used a replicator package for navision?