That's exactly what I've been using for making copies from DVD to VHS: Sima video enhancer. I was wondering if this device will do the work from VHS to DVD, but I am pretty sure it does.
There is an additional problem though, if the DVD is copy protected (almost all new releases), when I make DVD-VHS copies with Sima I always get copies with thin lines accross the screen, like flashes. When I had the video wires provided by Sima, the image quality was not that great, but got no lines; however, when I replaced the wires with better ones, the image improved a lot but then the lines came up.
If I use a back-up DVD copy (no copy protection) instead of the original DVD, there are no lines in the VHS copy.
Did you have any problem like this?