For any of you that need a SFI approved transmission shield for your Ford transmission we have found a great source for them.
They have new shields for the C4, C6 and AOD, as well as other make transmissions. The shields are well made (they look identical to a TSI brand shield to me), have new SFI stickers on them and this site has better prices than I have found elsewhere.
You can check them out here: C4 Transmission Shields This link is for the C4 shields but the site is very easy to navigate around on.
We will try and post a full review of the C4 shield we got in the near future but so far it looks like a real winner.