The games will depend on the format. For eg, some regions are running video formats in 'PAL' while others are running in 'NTSC'. So you need to check what format is being run in Argentina and Canada. If both are the same, there should be no issue. However, if they are different (for eg, Argentina is 'Pal'P and Canada is 'NTSC'), then you may have a problem.
You should buy the format being run in Canada since that's where the games would be running eventually. From what I've managed to figure out, PAL-N variant is used in Argentina. Source: http://en.wikipedia.org/wiki/PAL
You may wanna check out the game as well...because most of the ps3 games are region-free...so check the back cover of the game if its region free it will work....
All PS3 games will work on any PS3, regions don't matter at all.
The ONLY thing that you will have problems playing on your PS3 are movies (DVD, Blu-Ray) from different regions. US-NTSC, NTSC-J, PAL.