I did one of these a while back, using Great American ballpark at the YMCA & Lamar spot.
Here's PNC Park at the former Stateman's site. Eyeball-scaled as best I could using Google maps satellite & Google Earth.
It just barely fits, but any serious consideration would have to bundle in the Firestone building, and the Traffic & Transportation building behind it to fit the full footprint. Plus whatever ownership group would undoubtedly add other small buildings for team offices, team store, "ballpark village" amenities, etc.