There's an old saying about opinions resembling part of the human anatomy...
Mine is worth what you paid for it, but I'll chime in and say that getting a Fox or Smith that is original and opening the chokes, etc. to shoot steel isn't a great idea. To me, it would be like buying a rig of Mason Premier mallards to hunt over and then repainting them because "they don't look right". The Fox HE, LC Smith Wildfowl/Long Range and similar guns are what they are BECAUSE of the long barrels, tight chokes, etc. And, while you can argue that value doesn't matter, paying $7,000 for a Fox HE and making it a $3,500 gun after the modifications is a steep price to pay...
If you are willing to wait and hunt around, there are some that have been opened up, restocked, etc. that come up for sale once in a while, and they are generally priced lower because of the modifications. I saw an HE last night on a website that was selling for $3,000 or so that someone had put a Briley choke in ONE of the barrels...the gun was beat to pieces, probably needed a new stock, had barrel dents, etc. and was still selling for $3,000.
Honestly, if you buy a classic gun, I know the shells are outrageous, but spend the bucks on the "good" shells, even if it means it isn't your primary shooter.
You might consider a new gun, like a CZ, that can handle steel, or go a little higher in grade and try to find one of the Beretta SilverHawks, etc.
The other alternative, which might suit you well, is that the Parker Reproductions done a few years back actually did do a version of the 12 gauge DHE? grade which was safe for steel shot...not sure of the price range, but am guessing $4,000 to $6,000. They come up now and again on different sites and usually come with a canvas and leather case, etc.