The MSI MP54G4 (aka MSI MS-6833) seems to be readily available in the US now. I just picked one up from www.thenerds.net but a cheaper price can be found at newegg.com. It seems to work fine in my Sony SRX77.
The trick is to search for both the model name (MP54G4) and the part number (MS-6833) since some stores list the card one way and some the other. - todd
