You're not going to be happy with Weaver, MTH or Lionel's SD40-2 as the trucks sit too far inboard (this is a major spotting feature and what makes the Dash 2 so unique). I would recommend an Atlas or Lionel SD40 as it's more accurate. Not sure why MTH would spend money on new tooling for a SD45, but not spend the money on EMDs best Locomotive - the SD40-2
You can try to locate an old Central Locomotive Works SD40-2 and super detail it.