Cluster question

Hi all,

I have configured a domino server 6.5.1 (language pack spanish, and i want configure a domino server additional for test 6.5.4, with 10 users, can i do it with cluster? if only replicate their mail databases, and direct the location documents to that server (mail02) or how can i restrict only that users can access the server, or maybe a best option to do it…

Thanks in advanced