Best PA for the Money?

[Rockrz]

I know Lonman recommended using a Yamaha MG124CX board, and I've got that on my list.

But, I just came across this Yamaha PA system (2 speakers and a mixing board) at http://www.sweetwater.com/store/detail/StagePas600i for $899

Is this considered a good system, or would I do better to get the Yamaha MG124CX and then buy some speakers separately?

What I liked about the StagePas 600i system is that it claims to have the ability to prevent feedback. Is this claim a reality?

And, if getting a Yamaha board... would it be better to get Yamaha speakers? Just curious if having the same brand of electronics is better since the manufacturer's claim their components work best with their other components.