Most of the "out of the hood" blowers you're referring to are the old strait cut style roots huffers now made exclusively by Holly/Weiand. None of the aftermarket companies makes a lower manifold for them to fit the Modular engines (2v, 3v or 4V) so I doubt unless someone has spent considerable time and money into a custom project, you'll see one anytime soon. Not to mention their case design promotes the use of a top inlet style, instead of a rear inlet style like most of the ones on the market for our cars and no provisions for an intercooler.
Besides all that, the under hood Twin Screw kits supplied by Ford Racing, Kenne Bell and Saleen that are build specifically for our cars make enough power to burry an old strait cut roots unit of the same displacement anyway.