To run a business without off site backup, or any backup for that matter, is foolishness (we have 3 off site backup units that are updated every 6 hours).
The first thing to do in trying to recover your data is to remove the, labelled with slot number, disks then assemble the necessary tools as outlined by JavaLawyer. You can use either a USB/SATA adapter or an SATA hot swap caddy. We use the latter on a computer that is booted from an OS on DVD and recovered data is sent to our server storage bank.
In your case I would suggest that you use the USB/SATA adapter and boot your computer from a live Linux CD as it will be easier than trying to get an installable FS setup and working. The other thing, if you formatted the RAID array as Ext4 then I don't think NAS Data Recovery will see it (the version we have only sees Ext2 and Ext3.