I have an Epiphan VGA2USB external capture device for sale. It is in VERY good condition (has only been used 9/10 times since purchase). I am looking to sell this at a much reduced rate, or would also consider a straight swap for an external composite video capture device.
You can read a review on the product from the manufacturers website by searching for 'Epiphan VGA2USB' on google.
I also have examples of captured video quality if you wish to take a look.