Currently some of the best options currently available are: Marc-Andre Fleury, Darcy Kuemper, Jack Campbell, Braden Holtby, Martin Jones, Thomas Greiss and a few others, but there is definitely a market and need for them this year, so goalies wont be coming cheap.
The biggest prize in free agency though is Marc-Andre Fleury. After winning the Vezina just over a year ago as a member of the Vegas Golden Knights, he was traded to the Chicago Blackhawks for next to nothing. The Blackhawks did not thrive this season like they'd hoped after bringing in a good amount of players, so at the trade deadline they announced they would be starting a rebuild and traded Fleury to the Minnesota Wild.
Fleury started off very well for the Wild, setting organization records, but towards the end of the season, lost his game. He ended up losing the starting job in the playoffs as well after going 2-3-0 with a .906 SV% and 3.04GAA.
Pittsburgh fans would love to see him return, im also sure Wild fans would like to see him re-sign after quickly becoming a fan favourite. If winning one-last cup is in his thoughts, Colorado would probably be his best bet though.