It was the way I ended my pain. I even verified that I had a EFI boot compatible drive by using the latest Ubuntu DVD and making that into a UEFI usb stick which worked but for obvious reasons I didn't want to put that in my SP.
I used my older version of this
http://www.zalman.com/global/product/Product_Read.php?Idx=750
Which basically takes an ISO and makes it into a DVD drive. I was amazed it worked but it was faultless.
Out of interest what program did you use to make the UEFI stick?
The Zalman thing is pretty cool, I guess soon even external DVD drives will be obsolete.
I don't know why they gave the Surface possibly the worst BIOS known to man, nothing is easy to do with it. I have never known trouble like this just to boot an iso! My firmware and bios appears to be working fine (just windows corrupted) yet nothing external will boot... why!