I've read a lot of posts about the ATX/MTX switch, and I've usually argued against the switch myself. If I was going to do it, I would try to buy a wrecked or otherwise dead MTX car, so that I would have all of the miscellaneous but absolutely essential parts.

95 Contour Zetec, ATX (wrecked, sitting in the barn) 95 Mystique Zetec, MTX 2000 Taurus SEL 3.0L Duratec 1994 Crown Victoria LX 4.6 V8 1993 Chevy Silverado 4.3 V6