Yes you can buy it and it will work assuming you use high enough firmware. You will be able to run it on every other PS3 if you backup your rif/act file (would be nice if you share it with pr0p0sitionJOE) he can than make the game available for all of us for use with PSNReact.
PS: If some has Okami HD and is willing to share the rif/act file I would be happy thx
You need a CFW which is able to have PSN access and meets the min FW game requirements. PSN game mostly are the game files and the activation files, so if you provide the activation files everybody can activate the game on his/her PS3
If you have a CFW you just can FTP the activation files to your PC and share them.