REST or SOAP in our environment?

Spring Web service
I am not sure what kind of web services and API are ideal for our environment or if we should not go web service way
This is the our case:
1. Two sub-applications A (with database- a) and B with ( database- b) as part of 1 big application

2. A has a XLS of some records (manually dropped at a location ,periodically)
3. A calls WebService to export data from XLS and loads into B's DB b-
- reads XLS and preprocesses and loads into B
- before loading processes for duplicate etc verification for invalidity of records
- updates db of B.
- also generated output xls based on preprocessing
4 All this happens runs periodically .

We are planning to make it Batch Service using Spring Batch.
Also we are highly confused between REST or SOAP web service?

We have to make technology decision heere and not much acquainted. Since we are updating DBs and
REST doesnt have security mechanism , i was thinking of going SOAP way.
And using spring batch API for time-scheduling.
Our whole application is Spring 3.0 based on JDK6.