Aurora R7 - questions about hard disk capacity and upgrades

I have some easy questions, but I am getting conflicting answers from Dell. 

I recently bought a Dell Alienware Aurora R7.  It came with an SSD and 3.5" hard disk (2TB) pre-installed.  I want to know:

1.  What are my options to install additional hard drives (leaving the current one in place).  My preference would be to install one additional 4TB HD to use for backup and storage.  I have been told two conflicting things:

• I can install 2 2.5" HDs, each with a maximum capacity of 1 TB, but no additional 3.5" drives; that is, I can have a total of 4 drives (SSD, 1-3.5" (up to 4 TB) and 2-2.5" drives (up to 1 TB each)). 
• I have separately been told by Dell that I can install 2 2.5" HDs, each with a maximum capacity of 1 TB, plus an additional 3.5" drive; that is, I can have a total of 5 drives (SSD, 2-3.5" (up to 4 TB each) and 2-2.5" drives (up to 1 TB each). 

Which is correct?

2.  When I buy an additional HD to install, do I need to buy:

• SATA cable (assuming it is not bundled with the new HD)? 
• Power cable? 
• Hard-drive carrier (the blue thing -- presumably a Dell product -- into which the HD slips before being inserted into the hard-drive cage?

3.  Are there instructions anywhere for installing additional hard drives on the R7?  I can only find instructions for replacing drives.  I've added hard drives to other machines so I assume I can do it, but would be happier if I had instructions to refer to.

I know I could open up the R7 and look for the answers before buying the new HD, but I'd like to avoid that....

Devon