Alain,
Before any of us can recommend a suitable system - you need to tell us what the requirements are.
Live or home use?
Large or small size?
Is weight/size a problem?
Budget?
I use a pair of Mackie 450's for medium to large parties, and I have a small set of Roland self powered speakers on my studio desk at home with a 50W Samson subwoofer. That adds just the right ammnt of "punch" to the internal speakers. I also use it as a monitor for my 9kpro during recording.
Let us know your plans for these speakers, and we can suggest the right thing for the job.