I am not sure if any one other than maybe GT is still making them in steel. I know a few members here, myself included, and watching for the a late '80s Shogun or Nashbar to come our way at a decent price. They are ususally something like Tange Infinity or some other midlevel ChroMoly. I don't either made super highend ones, I believe Shogun may have made a shimano 600 equipped bike but the Nashbars may have topped out at a suntour Alpha 5000 or 105 group.
Are you looking for a custome made frame? I am sure most any builder will work with you on the style of stays but I am sure there will be an upcharge.
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“One morning you wake up, the girl is gone, the bikes are gone, all that's left behind is a pair of old tires and a tube of tubular glue, all squeezed out"
Sugar "Kane" Kowalczyk