I am interested in any suggestions you might have. I have different
heterogeneous databases (max 100 in number) which need to transfer
their data to a central SQL Server database. This is going to be one
way channel where central database consolidates the data which is
coming from different sources. Central location needs to be kept
up-to-date on a periodic basis. Each source can have max 50KB of data.
Is this transfer size decent enough to go through web services or
standard replication would be the better alternative?

Source database can be either SQL Server or Oracle. During the
synchronization period, each source will push the data to central
server at different time. Supposedly, concurrency is not going to be
an issue.

What approach should I pursue - what are the pros and cons of each?

Thanks in advance...