Security and privacy

Hi

> I want to set up moodle for 150 students, but will grow to a lot larger in the near future, and will need a large space to store files.
> ...
> to do all this will i need two servers?

That question belongs to "Hardware and Performance" forum http://moodle.org/mod/forum/view.php?id=596 (check the initial pointers given in its introduction).

In fact, you've posted the same question there, http://moodle.org/mod/forum/discuss.php?d=184720 which is not done
http://docs.moodle.org/20/en/Moodle.org_forums_Code_of_Conduct#Post_your_question_in_one_forum_only

Coming to the securiy part of your question:
> In summary i want to make sure my server or whatever i need to use is secure...
> the system will need to be safe and secure ( so files can't be tampered with, ...

Reading the what could happen to world class server administrators http://www.kernel.org/ ("Security breach on kernel.org" in the Site News) and the blunders star hackers make http://www.spiegel.de/international/world/0,1518,783778,00.html the term secure systems doesn't sound convincing there days.
;-(

> my knowledge is poor so exactly what i will need would be helpful..

Yet another reason to go for an external hoster. Read the pointers in the "Hardware and Performance" forum.