I would plan on finding a V8 K frame. Schumacher mounts are GREAT but there's something going on with the guy and his business and he's been WAY WAY behind in stock. Almost everything he was making is sold out and on back order and has been for well over a year or more now.
If you go the V8 k frame route, make sure you grab the pitman arm that attaches to the V8 K, the slant ones are different. Otherwise, everything else will bolt in just fine. You may want to see what rear axle is in your duster. If its the 7.25, you'll need to upgrade it to at least an 8.25 as the 318 will likely break the 7.25 if you get hard on it.
