Hello there, I've run into a little bit of trouble with my external hard drive. It's a pretty long story so I'll try to sum it up but still provide as much critical information as I can. I'm not extremely well versed with this stuff so please bear with me
First off, this is the external that I am using
http://www.amazon.ca/gp/product/B002QEBMCI/ref=oh_details_o04_s00_i00I hooked this up to my sister's Macbook to try and help her back up her data because she recently tried to install a new version of OS X Leopard which seems to have bricked her laptop. I made a LiveCD and proceeded to boot up Ubuntu on her laptop. After getting some advice from a friend, I went ahead and did this:

This is a screenshot of the Ubuntu terminal I had running. The
cp /dev/sda1 /dev/sdb1 command on the last line is the root of my problems. sda1 is the Macbook's hard drive, and sdb1 is my external drive. After using this command, terminal began working for about roughly 2 seconds, and it seems to have overwritten my external drive's structure and also renamed it from "Elements" to "EFI". This is what it looks like now when I hook it up to my Windows 7 PC:

Now I'm assuming the command I used in Ubuntu may have converted my NTFS partition to a FAT32, but I'm not entirely sure. I've contemplated trying to format the drive to NTFS but from what I've read, it's a risky procedure and I may end up losing data.
I've tried multiple data recovery suites (roughly 8 different kinds) and so far, R-Studio Network Edition and DiskDigger seem to be the most promising of them all. I've recovered most of my data except for a particular file type (.M2TS) which doesn't seem to be supported by a lot of these programs. Here are the scanning results that I get when I use R-Studio:
Recognized 3 is the new FAT32 partition that has some corrupt OS X installation files.
Recognized2 is the partition where all of my files are located intact with the appropriate file names and folder structures, but I can't seem to recover anything properly. When I try to recover a file, you can see what happens in the log found in the above screenshot near the bottom; "Closing attribute: parsed allocated size (#) differ from stored one (#)" and then "Recovering file (file path) failed. Can't read file to be recovered completely (801)."
That being said, I can recover
some files from the
Extra Found Files part of the scan in the previous screen I posted. It seems that the size of the original file plays a part in which files I can successfully recover or not; the bigger the file is, the least likely I am able to successfully recover it. Images seem to work universally but videos are a hit or miss. I've used another program called DiskDigger which seems to have been able to piece together a lot more files that I had, including videos, except for the notorious .m2ts files I'm looking for. DiskDigger, however, has not retained the structure of my files and folders and has inconveniently labelled all the files found as "sector(#)" where I'm assuming this refers to the sector of which the file was found. I can't complain though, at least I've found some working files

I guess my question to you all is what is my best course of action? Should I continue trying different recovery programs to see if one will happen to successfully recover all my files? Should I attempt to format the drive to NTFS or possibly even delete the FAT32 partition? Am I doing something wrong or missing something completely obvious?
I feel that because R-Studio actually detects my original folder structure and file names that there's still a chance to undo what I did, but that could just be wishful thinking.
Any input would be greatly appreciated!