Hi,
Thank you for posting in Symantec community.
I would be glad to answer your query.
I would strongly recommend to upgrade the existing SEPM to the latest version. After that there are couple of scenerios to consider
1) SEPM is having same hostname and IP address.
2) SEPM server has a different IP and same hostname
OR
SEPM server has a same IP and different hostanme
3) SEPM server has a differenet IP and different hostname.
I would suggest you to go through this article.
How to move SEPM from one server to another server.
https://www-secure.symantec.com/connect/articles/hot-move-sepm-one-server-another-server
If planning to install as a fresh install that is also possible, need to push Sylink.xml or new package on 30 clients per day according to that this process will take around 1 months time to migrate all 1000 clients.