Joomla Testbed Help

[JoseAmayo]

Hello,
I have searched extensively with no answers. I need to develop a Joomla website parallel to an existing HTML site and am not sure of the best way to do it. I can think of three options:
1) Develop the Joomla site on a separate site, and then backup and restore it on to the live server.
2) Install/develop Joomla on a dev folder and then when it is ready use a redirect to redirect visitors to the appropriate folder.
3) Install Joomla on the root of the live server and somehow hide the index.php file until it is ready, so that users see the existing index.html file. (I am not sure how to do this/if it is possible.)

Please let me know which of these, or any other, options is the best way to develop a Joomla site for an existing site.

[guido2004]

For me it's number 1. Or 2, but instead of redirecting to it, I'd reinstall it on the root when it's ready to go live.

[JoseAmayo]

Thanks Guido,
I have used Joomla before, but never like this. Re-installing on a different directory I understand, but how easy will it be to make sure that everything that was working on one install will immediately begin working on the second?