Red Hat :: Setting Up A Secure FTP Site Under RHEL 5.3

I have recently setup a RHEL 5.3 server primarily to be used as an Apache web server. I also now have a requirement to have this server also service SFTP requests for uploading/downloading files.

1. By default RHEL 5.3 allows SFTP (over TCP port 22). However when searching for SFTP site setup I've come across the fact that RedHat recommends using vsftpd. So if I configure vsftpd, what happens to the default SFTP and the ability to remotely use something like PuTTY to SSH into the server? Really looking to see if SFTP or vsftpd is best. Also, is vsftpd as or more secure than FTP over SSH?

2. I've set aside a separate disk parition (to keep it away from the system partition to help lock down security) for the SFTP site. So I want to use that as the default SFTP root directory structure. How can this be achieved?

3. My requirements dictate 3 separate directories need to be used, each with their own associated SFTP user. The user can only read/write it's own directory structure and cannot navigate out of it. Also there will be a SFTP super user able to navigate through each of the 3 directory structures mentioned, but will not be able to navigate out of it's home directory. Can this be done, if so how?

There will be no SSL certificates in play at the moment. I'm more concerned about getting things setup and working correctly first. However there may be a requirement to use them later. The site will be accessed over the Internet initially, hence the reason I'm looking to make it as secure as possible while getting it up and running quickly.