Create archive solution on seperate server
If you're planning on using Transactional or Merge Replication, then you won't be allowed to run a TRUNCATE command on any of your published tables in the Publisher Database. Please see the Microsoft BOL Frequently Asked Questions for Replication Administrators - Database Maintenance, specifically the first section called Why can't I run TRUNCATE TABLE on a published table?:

TRUNCATE TABLE is a DDL statement that does not log individual row deletions and does not fire DML triggers. It is not permitted because replication cannot track the changes caused by the operation: transactional replication tracks changes through the transaction log; merge replication tracks changes through DML triggers on published tables.

That being said, you can modify the properties of your published articles such that DELETE statements don't get replicated to the Subscriber Database, as detailed in this article Options to not replicate SQL Server DELETE commands. Or you can follow the second option of that article to modify the underlying stored procedure that would execute the DELETE statement, though I find the first solution cleaner.
Either of these options should help you achieve your goal.