I'm in Canada and just ran a bunch of wire for my AV system.
Amazon basic stranded copper will do you fine. I would not go thicker than 14 gauge as 12 gauge may not fit those spring loaded terminals. 16 gauge would be thick enough for those speakers. Anything from Monoprice is good value as well. You can purchase crimp on pins if you want metal pins to fit the speaker terminals but bare wire is ok for your speakers. Strip off about 1cm or 3/8" of insulation.
The linked spool is 50ft minimum. If you only need 10ft or 3m of wire, you can go to the hardware store and get 14 gauge lamp cord by the foot. As long as it's stranded copper it's ok.