I would use the Athearns. If you want fantastic detail, PSC has leaf spring arch bars for relative cheap. You need wheels, and drilling skills.
There were lots of different arch bar designs - in addition to wheelbases, the bottom bar may or may not drop down. Journal box lids were different from one to the next. Not sure I have any useful photos, but I will look.
Yeah, found the PSC castings. See above.