Jims Mobile make these types of telescopes, the only problem I see other than having three mirrors (excess cost) on one of the folded newt designs is that you have a large Secondary obstruction with the three mirror system and the two. The two mirror system is the same as a typical newt but the mirror is angled less to allow the focuser to be bought further down the tube, but in some cases at a awkward angle. In any case the secondary mirror would be much bigger so the light cone will fit onto it, as the distance from Focuser to secondary is somewhat larger. Its a hit and miss game. I would say the design would be more benificial in a Larger newt 18" and above, rather than a small diameter telescope that does not need the restricted heights. Anyway check out this page, tells you a little.
http://johanneswilm.org/mike/telescope/
You could also work with instead of a flat secondary, have a convex secondary to magnify the image before hitting the third mirror. (I think thats how it works.) But then it would be a folded cassergrain
Good luck.