No, it won't work ... you can't mix SAS and SATA, or SSD and HDD.

Create a RAID 1 with the two disks, then Reconfigure to a RAID 5 when the other arrives, then just hope your SSD's work. There are several issues you may encounter with unsupported drives, SSD's in particular. If you are lucky, they will work and the LED's will only show they are offline.

I thought reconfiguring to a different RAID level will destroy any and all data? The SSD's do work as i have 2 as the VD0 without any flashing amber lights ans the performance is there.

http://www.dell.com/support/article/us/en/04/SLN156106

While that article does not specifically say it does NOT destroy data, it is worded is such a way to suggest data is NOT destroyed in a RAID level migration. That article aslo does NOT apply to the 6i. Can anyone confirm? 

I will proceed according to your good word! Could you supply me with either a document that walks me through this or give a summary here?

Not sure what you need assistance with, you cannot mix SAS and SSD drives in the same array. See post by Flash.

To add a third SSD to a 2-disk SSD RAID 1 to create a RAID 5: Using OMSA, go to Storage, PERC, Virtual Disks, and select Reconfigure from the drop-down menu of Available Tasks. This will start a wizard to select the disk to add and the RAID level.

Do note that you won't have TRIM, garbage collection and/or full bandwidth to an SSD if you use the PERC6i.

I'd suggest to at least upgrade to a PERC H700. You may have to buy different cables in that case as well though.

So i found this H700:

http://www.ebay.com/itm/Dell-PowerEdge-R610-PERC-H700-Kit-512MB-Cache-6GB-s-SAS-RAID-Controller-XXFVX-/162226626388?hash=item25c575df54

This looks like it will work, yes?

RAID Level Migration and Online Capacity Expansion are designed to be done ONLINE and are NOT data-destructive. This is the case with PERC 3/4/5/6, and H7x00 controllers.

Is the one i linked to in my last post "a lower-end h700"?