Indeed, it's a much more agreeable solution than implementing a minimum price of 5 dollars for everything, which appears to be an unwelcome and inflationary approach. This is precisely the type of price inflation that raises concerns about its potential manifestation here in Argentina.Panama doesn't quite fit the typical scenario of dollarization. As I understand it, both the Balboa and the Dollar were established as legal tender in newly independent Panama back in 1904. While USD banknotes are in circulation (I've never encountered a Balboa banknote, if they exist), the coin issue was resolved by minting Balboa coins.
On a personal note, the idea of Argentina minting its own silver "dollars" could be a viable alternative, although it seems unlikely, especially considering the current silver price reaching 23 bucks. Even a quarter-ounce coin would hold around 6 bucks worth of silver at that rate.
As you mentioned before, obtaining old Morgans and Walking Liberty coins appears to be quite challenging here.